diff --git a/frontend/packages/agent/src/app.js b/frontend/packages/agent/src/app.js
index e1f3881d..7d2b424e 100644
--- a/frontend/packages/agent/src/app.js
+++ b/frontend/packages/agent/src/app.js
@@ -1473,245 +1473,6 @@ window.marked = marked;
       }
       return d;
     }
-    // Generic args-pretty-printer for unknown / extra-MCP tools. The
-    // built-in switch handles the common claude/hyperhive tools; this
-    // is the fallback so an `mcp__matrix__send_message` or similar
-    // doesn't dump raw JSON. Heuristics: single string-valued field →
-    // `Name field: "value"`; single dict-valued field → `Name field
-    // {…}`; otherwise compact JSON. Always trimmed to fit a row.
-    function fmtArgsGeneric(name, input) {
-      const keys = Object.keys(input || {});
-      if (keys.length === 0) return name + '()';
-      if (keys.length === 1) {
-        const k = keys[0];
-        const v = input[k];
-        if (typeof v === 'string') {
-          const oneline = v.replace(/\s+/g, ' ').trim();
-          return name + ' ' + k + ': ' + JSON.stringify(trim(oneline, 100));
-        }
-        if (typeof v === 'number' || typeof v === 'boolean') {
-          return name + ' ' + k + ': ' + JSON.stringify(v);
-        }
-      }
-      // Multi-field: render `k: v` pairs with strings/numbers inlined and
-      // anything else summarised by type so the row stays readable.
-      const pretty = keys.slice(0, 4).map((k) => {
-        const v = input[k];
-        if (v == null) return k + ': null';
-        if (typeof v === 'string') {
-          const oneline = v.replace(/\s+/g, ' ').trim();
-          return k + ': ' + JSON.stringify(trim(oneline, 40));
-        }
-        if (typeof v === 'number' || typeof v === 'boolean') return k + ': ' + v;
-        if (Array.isArray(v)) return k + `: [${v.length}]`;
-        return k + ': {…}';
-      });
-      const tail = keys.length > 4 ? ' …+' + (keys.length - 4) : '';
-      return name + ' ' + pretty.join(' · ') + tail;
-    }
-    // Per-tool glyph for the tool-use row prefix — gives each hive / MCP /
-    // built-in tool a distinctive icon instead of a generic wrench, so the
-    // scrollback is scannable at a glance. Exact tool names first, then
-    // MCP-server family fallbacks, then a generic wrench default.
-    const TOOL_ICONS = {
-      'mcp__hyperhive__send': '📤',
-      'mcp__hyperhive__recv': '📥',
-      'mcp__hyperhive__ask': '❓',
-      'mcp__hyperhive__answer': '✍️',
-      'mcp__hyperhive__remind': '⏰',
-      'mcp__hyperhive__set_status': '🏷️',
-      'mcp__hyperhive__get_loose_ends': '🪢',
-      'mcp__hyperhive__cancel_loose_end': '✂️',
-      'mcp__hyperhive__ack_until': '✅',
-      'mcp__hyperhive__get_agent_meta': 'ℹ️',
-      'mcp__hyperhive__request_next_turn': '⏩',
-      'mcp__hyperhive__restart': '↻',
-      'mcp__hyperhive__kill': '⏹️',
-      'mcp__hyperhive__start': '▶️',
-      'mcp__hyperhive__update': '🔄',
-      'mcp__hyperhive__list_containers': '📋',
-      'mcp__hyperhive__get_logs': '📜',
-      'mcp__hyperhive__get_host_journal': '📜',
-      'mcp__matrix__read_room': '📖',
-      'mcp__matrix__mark_read': '👁️',
-      'mcp__matrix__list_rooms': '📋',
-      'mcp__matrix__list_room_members': '📋',
-      'mcp__matrix__list_invites': '📋',
-      'mcp__bash__kill': '🛑',
-      Read: '📖', Write: '💾', Edit: '✏️', Glob: '🔍', Grep: '🔍',
-    };
-    function toolIcon(name) {
-      if (TOOL_ICONS[name]) return TOOL_ICONS[name];
-      if (typeof name === 'string') {
-        if (name.startsWith('mcp__matrix__')) return '💬';
-        if (name.startsWith('mcp__bash__')) return '🖥️';
-        if (name.includes('schedule')) return '⏱️';
-        // request_init_config / request_update_meta_inputs
-        if (name.startsWith('mcp__hyperhive__request_')) return '📦';
-      }
-      return '🔧';
-    }
-    // Shorten a matrix room id or alias for display. Room ids (!xxx:server)
-    // are trimmed to the first 8 local chars; aliases (#name:server) are
-    // returned as-is (they're already readable). Falls back to the raw
-    // value truncated.
-    function fmtRoom(r) {
-      if (!r) return '?';
-      if (r.startsWith('!')) return r.slice(0, r.indexOf(':') > 0 ? r.indexOf(':') : 9);
-      if (r.startsWith('#')) return r.split(':')[0] || r;
-      return trim(r, 20);
-    }
-    // Shorten @user:server → @user.
-    function fmtUser(u) {
-      if (!u) return '?';
-      const colon = u.indexOf(':');
-      return colon > 0 ? u.slice(0, colon) : u;
-    }
-    // Pretty-print a tool call: per-known-tool format, fallback to JSON
-    // for unknown tools.
-    function fmtToolUse(c) {
-      const name = c.name || '';
-      const input = c.input || {};
-      const short = name.startsWith('mcp__hyperhive__')
-        ? name.slice('mcp__hyperhive__'.length) + '*'
-        : name.startsWith('mcp__bash__')
-          ? name.slice('mcp__bash__'.length) + '*'
-          : name.startsWith('mcp__matrix__')
-            ? name.slice('mcp__matrix__'.length) + '*'
-            : name;
-      switch (name) {
-        case 'Read':       return short + ' ' + (input.file_path || '');
-        case 'Write':      return short + ' ' + (input.file_path || '');
-        case 'Edit':       return short + ' ' + (input.file_path || '');
-        case 'Glob':       return short + ' ' + (input.pattern || '');
-        case 'Grep':       return short + ' ' + (input.pattern || '');
-        case 'Bash':       return short + (input.run_in_background ? ' [bg]' : '')
-          + ' $ ' + (input.command || '');
-        case 'TodoWrite':  return short + ' (' + ((input.todos || []).length) + ' items)';
-        case 'mcp__hyperhive__send': return short + ' → ' + (input.to || '?') + ': '
-          + JSON.stringify(input.body || '').slice(0, 80);
-        case 'mcp__hyperhive__recv': {
-          // Surface the long-poll wait + batch size — a bare `recv()` row
-          // hides whether the agent is parking a turn (wait_seconds) or
-          // draining a burst (max).
-          const parts = [];
-          if (input.wait_seconds != null) parts.push('wait ' + input.wait_seconds + 's');
-          if (input.max != null) parts.push('max ' + input.max);
-          return short + (parts.length ? ' ' + parts.join(' · ') : '()');
-        }
-        case 'mcp__hyperhive__kill':          return short + ' ' + (input.name || '');
-        case 'mcp__hyperhive__restart':       return short + ' ' + (input.name || '');
-        case 'mcp__hyperhive__start':         return short + ' ' + (input.name || '');
-        case 'mcp__hyperhive__update':        return short + ' ' + (input.name || '');
-        case 'mcp__hyperhive__ack_until':
-          return short + ' ≤' + (input.up_to != null ? input.up_to : '?');
-        case 'mcp__hyperhive__get_logs':
-          return short + ' ' + (input.agent || '?')
-            + (input.lines != null ? ' · ' + input.lines + 'L' : '');
-        case 'mcp__hyperhive__get_host_journal': {
-          const parts = [];
-          if (input.container) parts.push(input.container);
-          else if (input.unit) parts.push(input.unit);
-          if (input.grep) parts.push('/' + input.grep + '/');
-          if (input.lines != null) parts.push(input.lines + 'L');
-          return short + (parts.length ? ' ' + parts.join(' · ') : '()');
-        }
-        case 'mcp__hyperhive__remind': {
-          // Surface when the reminder fires + the first line of the message.
-          // `delay_seconds` → human-readable "+5m"; `at_unix_timestamp` →
-          // "at HH:MM"; message truncated to fit.
-          let when = '';
-          if (input.delay_seconds != null) {
-            const s = input.delay_seconds;
-            when = '+' + (s < 60 ? s + 's' : s < 3600 ? Math.round(s / 60) + 'm'
-                                                        : (s / 3600).toFixed(1) + 'h');
-          } else if (input.at_unix_timestamp != null) {
-            when = 'at ' + new Date(input.at_unix_timestamp * 1000)
-              .toISOString().slice(11, 16) + 'Z';
-          }
-          const msg = String(input.message || input.file_path || '').replace(/\s+/g, ' ').trim();
-          return short + (when ? ' ' + when : '') + (msg ? ' "' + trim(msg, 60) + '"' : '');
-        }
-        case 'mcp__hyperhive__request_init_config':
-          return short + ' ' + (input.name || '?');
-        case 'mcp__hyperhive__request_update_meta_inputs': {
-          const ins = Array.isArray(input.inputs) && input.inputs.length
-            ? '[' + input.inputs.slice(0, 4).join(', ')
-              + (input.inputs.length > 4 ? ', …' : '') + ']'
-            : 'all';
-          return short + ' ' + ins;
-        }
-        case 'mcp__hyperhive__list_schedules':
-          return short + '()';
-        case 'mcp__hyperhive__cancel_schedule':
-          return short + ' #' + (input.id != null ? input.id : '?')
-            + (Array.isArray(input.targets) && input.targets.length
-              ? ' [' + input.targets.join(', ') + ']' : ' all');
-        case 'mcp__hyperhive__fire_schedule_now':
-          return short + ' #' + (input.id != null ? input.id : '?');
-        case 'mcp__hyperhive__edit_schedule': {
-          const parts = ['#' + (input.id != null ? input.id : '?')];
-          if (input.body != null) parts.push('body');
-          if (input.interval_seconds != null) parts.push('interval');
-          if (input.next_fire_at_unix != null) parts.push('next');
-          if (input.targets_add && input.targets_add.length) parts.push('+' + input.targets_add.length + ' tgt');
-          if (input.targets_remove && input.targets_remove.length) parts.push('-' + input.targets_remove.length + ' tgt');
-          return short + ' ' + parts.join(' · ');
-        }
-        case 'mcp__hyperhive__request_schedule_prompt': {
-          const tgts = Array.isArray(input.targets) ? input.targets : [];
-          const when = input.first_fire_at_unix != null
-            ? new Date(input.first_fire_at_unix * 1000).toISOString().slice(11, 16) + 'Z'
-            : '?';
-          return short + ' → ' + (tgts.length ? tgts.join(', ') : '?') + ' at ' + when
-            + (input.interval_seconds != null ? ' +' + input.interval_seconds + 's' : '');
-        }
-        case 'mcp__bash__run': {
-          // Rich renderer handles the full body; this summary covers any
-          // fallback path and the details summary line.
-          const firstLine = String(input.cmd || '').split('\n')[0];
-          return short + ' $ ' + trim(firstLine.trim(), 72);
-        }
-        case 'mcp__bash__status':
-          return short + ' id:' + (input.id || '?')
-            + (input.wait_seconds != null ? ' · wait ' + input.wait_seconds + 's' : '');
-        case 'mcp__bash__kill':
-          return short + ' ' + (input.id || '?') + (input.force ? ' [force]' : '');
-        case 'mcp__hyperhive__set_status':
-          return short + ' "' + trim(String(input.text || ''), 60) + '"';
-        case 'mcp__hyperhive__get_loose_ends':
-          return short + (input.agent ? ' [' + input.agent + ']' : '()');
-        case 'mcp__hyperhive__get_agent_meta':
-          return short + (input.name ? ' ' + input.name : '()');
-        case 'mcp__hyperhive__cancel_loose_end':
-          return short + ' ' + (input.kind || '?') + ' #' + (input.id != null ? input.id : '?');
-        case 'mcp__matrix__read_room':
-          return short + ' ' + fmtRoom(input.room)
-            + (input.limit != null ? ' [' + input.limit + ']' : '');
-        case 'mcp__matrix__mark_read':
-          return short + ' ' + fmtRoom(input.room);
-        case 'mcp__matrix__send_message':
-          return short + ' → ' + fmtRoom(input.room) + ': '
-            + JSON.stringify(trim(String(input.body || ''), 50));
-        case 'mcp__matrix__send_dm':
-          return short + ' → ' + fmtUser(input.user_id) + ': '
-            + JSON.stringify(trim(String(input.body || ''), 50));
-        case 'mcp__matrix__send_reply':
-          return short + ' → ' + fmtRoom(input.room) + ': '
-            + JSON.stringify(trim(String(input.body || ''), 50));
-        case 'mcp__matrix__send_reaction':
-          return short + ' ' + fmtRoom(input.room) + ' ' + (input.key || '?');
-        case 'mcp__matrix__join_room':
-          return short + ' ' + fmtRoom(input.room);
-        case 'mcp__matrix__open_dm':
-          return short + ' ' + fmtUser(input.user_id);
-        case 'mcp__matrix__invite_user':
-          return short + ' ' + fmtUser(input.user_id) + ' → ' + fmtRoom(input.room);
-        case 'mcp__matrix__download_file':
-          return short + ' ' + fmtRoom(input.room);
-        default: return fmtArgsGeneric(short, input);
-      }
-    }
     // Build a "rich" tool_use row for tools whose input has a body we
     // want the operator to see in full. Returns null for any other tool
     // so the caller falls back to the flat-row path.
@@ -1721,6 +1482,7 @@ window.marked = marked;
     function renderRichToolUse(c, api) {
       const name = c.name || '';
       const input = c.input || {};
+      const icon = c._icon || '🔧';
       if (name === 'Write' || name === 'Edit') {
         const path = input.file_path || '?';
         let body;
@@ -1746,7 +1508,7 @@ window.marked = marked;
         // the CSS disclosure caret leads the text).
         const summary = name + ' ' + path + ' · '
           + (minus ? '-' + minus + ' ' : '') + '+' + plus;
-        return api.detailsDiff('tool-use', summary, body, toolIcon(name));
+        return api.detailsDiff('tool-use', summary, body, icon);
       }
       // Message-bearing tools render default-open with a markdown body so
       // the operator sees the content without an extra click. send / ask
@@ -1757,7 +1519,7 @@ window.marked = marked;
         const lines = body.split('\n').length;
         return detailsOpenMd(api, 'tool-use',
           'send → ' + to + (lines > 1 ? ` · ${lines}L` : ''),
-          body, toolIcon(name));
+          body, icon);
       }
       if (name === 'mcp__hyperhive__ask') {
         const to = input.to || 'operator';
@@ -1765,7 +1527,7 @@ window.marked = marked;
         const lines = q.split('\n').length;
         const d = detailsOpenMd(api, 'tool-use',
           'ask → ' + to + (lines > 1 ? ` · ${lines}L` : ''),
-          q, toolIcon(name));
+          q, icon);
         // When the ask targets the operator, mount an inline answer
         // slot in the live terminal — see docs/web-ui.md::Per-agent
         // page (Ask → operator inline-answer binding) for the slot
@@ -1795,7 +1557,7 @@ window.marked = marked;
         const lines = a.split('\n').length;
         return detailsOpenMd(api, 'tool-use',
           'answer #' + id + (lines > 1 ? ` · ${lines}L` : ''),
-          a, toolIcon(name));
+          a, icon);
       }
       // Bash task runner — show full command in an expandable pre block so
       // multi-line scripts are readable. Summary uses the first line so the
@@ -1804,7 +1566,7 @@ window.marked = marked;
         const cmd = String(input.cmd || '');
         const firstLine = cmd.split('\n')[0];
         const summary = 'run* $ ' + trim(firstLine.trim(), 72);
-        return api.details('tool-use', summary, '$ ' + cmd, toolIcon(name));
+        return api.details('tool-use', summary, '$ ' + cmd, icon);
       }
       return null;
     }
@@ -1922,101 +1684,28 @@ window.marked = marked;
     // then "✓ done") for what's really one event.
     const updatePluginInstall = makeCoalescer('note');
     function renderStream(v, api) {
-      // Drop claude's result line and rate-limit — noise. TurnEnd
-      // communicates pass/fail; rate-limit events are noisy status chatter.
-      if (v.type === 'rate_limit_event') return;
-      if (v.type === 'result') return;
-      // `system` events: `init` is silent startup noise; `api_retry`
-      // and `api_error` get human-readable notes; unknown subtypes get a
-      // muted line rather than a raw-JSON dump in the loud `sys` colour.
+      // Backend pre-computes `_category` on all known event types.
+      // "drop" covers: type=result, type=rate_limit_event, and system/init.
+      if (v._category === 'drop') return;
+
       if (v.type === 'system') {
-        if (v.subtype === 'init') return;
-        if (v.subtype === 'api_retry') {
-          const parts = ['⚠ api retry'];
-          if (v.attempt != null && v.max_retries != null)
-            parts.push(v.attempt + '/' + v.max_retries);
-          if (v.error) parts.push(String(v.error));
-          else if (v.error_status) parts.push('HTTP ' + v.error_status);
-          if (v.retry_delay_ms != null)
-            parts.push(Math.round(v.retry_delay_ms) + 'ms');
-          api.row('note', parts.join(' · '));
+        const cat = v._category;
+        const summary = v._summary;
+        // thinking_tok: collapse many ticks into one in-place counter row.
+        if (cat === 'thinking_tok') {
+          updateThinkingTokens(api, summary || 'thinking…');
           return;
         }
-        if (v.subtype === 'api_error') {
-          const msg = v.error || v.message
-            || (v.error_status ? 'HTTP ' + v.error_status : 'unknown');
-          api.row('note stderr', '✗ api error · ' + msg);
-          return;
-        }
-        // Live thinking-token counter — claude streams many of these per
-        // turn (a running `estimated_tokens` total while it thinks). Collapse
-        // consecutive ticks into ONE in-place-updating row instead of a note
-        // per tick (see `makeCoalescer` above).
-        if (v.subtype === 'thinking_tokens') {
-          const n = v.estimated_tokens;
-          const text = 'thinking … '
-            + (n != null ? '~' + Number(n).toLocaleString() + ' tokens' : '');
-          updateThinkingTokens(api, text);
-          return;
-        }
-        // plugin_install: claude is loading/finishing a plugin (MCP server or
-        // slash-command provider). Show the status so the operator knows when
-        // a fresh session is loading its toolset.
+        // plugin_install: coalesced in-place row while the plugin loads.
         if (v.subtype === 'plugin_install') {
-          const status = v.status === 'completed' ? '✓ done'
-                       : v.status === 'started'   ? 'loading…'
-                       :                            (v.status || '?');
-          updatePluginInstall(api, '⚙ plugin install · ' + status);
+          updatePluginInstall(api, summary || '⚙ plugin install');
           return;
         }
-        // commands_changed: the set of available slash commands changed (usually
-        // right after plugin_install). Show the count in the summary; expand to
-        // see the full list.
-        if (v.subtype === 'commands_changed') {
-          const cmds = Array.isArray(v.commands) ? v.commands : [];
-          if (!cmds.length) {
-            api.row('note', '⚙ commands changed · (empty)');
-            return;
-          }
-          const summary = '⚙ commands changed · ' + cmds.length + ' available';
-          const body = cmds.map((c) => {
-            const aliases = c.aliases && c.aliases.length
-              ? '  [/' + c.aliases.join(', /') + ']' : '';
-            return '/' + c.name + aliases;
-          }).join('\n');
-          api.details('note', summary, body);
-          return;
-        }
-        // compact_boundary: claude completed a compaction pass. The metadata
-        // carries pre/post token counts, duration, and the trigger (manual vs
-        // auto). Show a single summary line so the operator can gauge how much
-        // context was shed.
-        if (v.subtype === 'compact_boundary') {
-          const m = v.compact_metadata || {};
-          const parts = ['⚙ compact'];
-          if (m.trigger) parts.push(m.trigger);
-          if (m.pre_tokens != null && m.post_tokens != null) {
-            const fmtTok = (n) => n >= 1_000_000 ? (n / 1_000_000).toFixed(1) + 'M'
-                                : n >= 1_000      ? Math.round(n / 1000) + 'k'
-                                :                   String(n);
-            parts.push(fmtTok(m.pre_tokens) + '→' + fmtTok(m.post_tokens) + ' tokens');
-          }
-          if (m.duration_ms != null) {
-            const ms = m.duration_ms;
-            parts.push(ms < 1000 ? ms + 'ms' : (ms / 1000).toFixed(1) + 's');
-          }
-          api.row('note', parts.join(' · '));
-          return;
-        }
-        // Bare `status` ticks (claude's own generic "still working" signal,
-        // no detail beyond the label) — collapse consecutive ticks into one
-        // updating row instead of a fresh note each (see `makeCoalescer`
-        // above). When the harness state is `compacting` (set by the
-        // `turn_state_changed` SSE event), show elapsed time via `stateSince`
-        // — the same source the state badge uses — so the terminal reflects
-        // compaction progress; otherwise fall back to the generic label.
+        // status: backend provides the base label; when the harness state is
+        // `compacting` we override with elapsed time from `stateSince` — a
+        // client-side wall-clock value the backend can't know at emit time.
         if (v.subtype === 'status') {
-          let label = '⚙ status';
+          let label = summary || '⚙ status';
           if (stateName === 'compacting') {
             const elapsed = Math.round((Date.now() - stateSince) / 1000);
             label = '⚙ compact · ' + elapsed + 's…';
@@ -2024,10 +1713,13 @@ window.marked = marked;
           updateStatus(api, label);
           return;
         }
-        // Other system subtypes (context_window_exceeded, etc.) — render a
-        // muted note with the subtype label; reserve the loud orange `sys`
-        // catch-all for truly unrecognised top-level types.
-        api.row('note', '⚙ ' + (v.subtype || 'system'));
+        // details: expandable row with _summary as header, _body as content.
+        if (cat === 'details') {
+          api.details('note', summary || '⚙ ' + (v.subtype || ''), v._body || '');
+          return;
+        }
+        // note (and any unknown category): single summary line.
+        api.row('note', summary || '⚙ ' + (v.subtype || 'system'));
         return;
       }
       // Background-task subagent events (claude's `Task` tool spawns
@@ -2052,8 +1744,15 @@ window.marked = marked;
           }
           else if (c.type === 'tool_use') {
             if (c.id && c.name) toolNameById.set(c.id, c.name);
-            if (!renderRichToolUse(c, api)) {
-              api.row('tool-use', fmtToolUse(c), toolIcon(c.name));
+            // `_category: "rich"` is stamped by the backend on tools that
+            // have full-body renderers (Write/Edit diffs, send/ask/answer
+            // message bodies). Flat-row tools use backend _icon/_summary.
+            if (c._category === 'rich') {
+              if (!renderRichToolUse(c, api)) {
+                api.row('tool-use', c._summary || c.name || '?', c._icon || '🔧');
+              }
+            } else {
+              api.row('tool-use', c._summary || c.name || '?', c._icon || '🔧');
             }
           }
         }
diff --git a/hive-agent/src/stream_enrich.rs b/hive-agent/src/stream_enrich.rs
index 241e16dd..1fd37ac3 100644
--- a/hive-agent/src/stream_enrich.rs
+++ b/hive-agent/src/stream_enrich.rs
@@ -36,6 +36,13 @@ use serde_json::{Value, json};
 /// already-enriched values if the DB is ever pre-populated by a future phase).
 pub fn enrich(v: &mut Value) {
     match v.get("type").and_then(Value::as_str).unwrap_or("") {
+        // Top-level result/rate_limit_event are drop-category noise — stamp
+        // the same category the frontend uses to silently discard them.
+        "result" | "rate_limit_event" => {
+            if let Some(obj) = v.as_object_mut() {
+                obj.entry("_category").or_insert_with(|| json!("drop"));
+            }
+        }
         "system" => enrich_system(v),
         "assistant" => enrich_assistant(v),
         _ => {}
@@ -246,6 +253,7 @@ fn is_rich_tool(name: &str) -> bool {
         name,
         "Write"
             | "Edit"
+            | "mcp__bash__run"
             | "mcp__hyperhive__send"
             | "mcp__hyperhive__ask"
             | "mcp__hyperhive__answer"
@@ -300,10 +308,9 @@ fn tool_icon_fallback(name: &str) -> &'static str {
 }
 
 // ---------------------------------------------------------------------------
-// tool_use summary formatter
+// tool_use summary formatter — dispatch to per-family sub-functions
 // ---------------------------------------------------------------------------
 
-#[allow(clippy::too_many_lines)]
 fn fmt_tool_use(name: &str, input: &Value) -> String {
     // Short name: strip the MCP server prefix for display.
     let short = if let Some(rest) = name.strip_prefix("mcp__hyperhive__") {
@@ -316,6 +323,20 @@ fn fmt_tool_use(name: &str, input: &Value) -> String {
         name.to_owned()
     };
 
+    if name.starts_with("mcp__hyperhive__") {
+        fmt_hyperhive_tool(name, &short, input)
+    } else if name.starts_with("mcp__bash__") {
+        fmt_bash_tool(name, &short, input)
+    } else if name.starts_with("mcp__matrix__") {
+        fmt_matrix_tool(name, &short, input)
+    } else {
+        fmt_builtin_tool(name, &short, input)
+    }
+}
+
+/// Built-in claude tools: Read/Write/Edit/Glob/Grep/Bash/TodoWrite and any
+/// unknown tool that doesn't carry a known MCP server prefix.
+fn fmt_builtin_tool(name: &str, short: &str, input: &Value) -> String {
     match name {
         "Read" | "Write" | "Edit" => format!("{short} {}", sv(input, "file_path")),
         "Glob" | "Grep" => format!("{short} {}", sv(input, "pattern")),
@@ -338,6 +359,13 @@ fn fmt_tool_use(name: &str, input: &Value) -> String {
                 .map_or(0, Vec::len);
             format!("{short} ({n} items)")
         }
+        _ => fmt_args_generic(short, input),
+    }
+}
+
+/// `mcp__hyperhive__*` tools.
+fn fmt_hyperhive_tool(name: &str, short: &str, input: &Value) -> String {
+    match name {
         "mcp__hyperhive__send" => {
             let body = trim_str(&sv(input, "body"), 80);
             format!("{short} → {}: {}", sv(input, "to"), json_str(&body))
@@ -395,42 +423,111 @@ fn fmt_tool_use(name: &str, input: &Value) -> String {
                 format!("{short} {}", parts.join(" · "))
             }
         }
-        "mcp__hyperhive__remind" => {
-            let when = if let Some(s) = input.get("delay_seconds").and_then(Value::as_u64) {
-                if s < 60 {
-                    format!("+{s}s")
-                } else if s < 3_600 {
-                    format!("+{}m", s / 60)
-                } else {
-                    #[allow(clippy::cast_precision_loss)]
-                    let h_f = s as f64 / 3_600.0;
-                    format!("+{h_f:.1}h")
-                }
-            } else if let Some(ts) = input.get("at_unix_timestamp").and_then(Value::as_u64) {
-                let h = (ts % 86_400) / 3_600;
-                let m = (ts % 3_600) / 60;
-                format!("at {h:02}:{m:02}Z")
-            } else {
-                String::new()
-            };
-            let msg_raw = input
-                .get("message")
-                .or_else(|| input.get("file_path"))
-                .and_then(Value::as_str)
-                .unwrap_or("");
-            let msg = trim_str(&msg_raw.replace(char::is_whitespace, " "), 60);
-            let when_part = if when.is_empty() {
-                String::new()
-            } else {
-                format!(" {when}")
-            };
-            let msg_part = if msg.is_empty() {
-                String::new()
-            } else {
-                format!(" \"{msg}\"")
-            };
-            format!("{short}{when_part}{msg_part}")
+        "mcp__hyperhive__remind" => fmt_hyperhive_remind(short, input),
+        "mcp__hyperhive__request_update_meta_inputs"
+        | "mcp__hyperhive__list_schedules"
+        | "mcp__hyperhive__cancel_schedule"
+        | "mcp__hyperhive__fire_schedule_now"
+        | "mcp__hyperhive__edit_schedule"
+        | "mcp__hyperhive__request_schedule_prompt" => {
+            fmt_hyperhive_schedule_tool(name, short, input)
         }
+        "mcp__hyperhive__set_status" => {
+            format!("{short} \"{}\"", trim_str(&sv(input, "text"), 60))
+        }
+        "mcp__hyperhive__get_loose_ends" => {
+            let agent = input
+                .get("agent")
+                .and_then(Value::as_str)
+                .map_or_else(|| "()".to_owned(), |a| format!(" [{a}]"));
+            format!("{short}{agent}")
+        }
+        "mcp__hyperhive__get_agent_meta" => {
+            let name_part = input
+                .get("name")
+                .and_then(Value::as_str)
+                .map_or_else(|| "()".to_owned(), |n| format!(" {n}"));
+            format!("{short}{name_part}")
+        }
+        "mcp__hyperhive__cancel_loose_end" => {
+            let id = input
+                .get("id")
+                .and_then(Value::as_u64)
+                .map_or_else(|| "?".to_owned(), |n| n.to_string());
+            format!("{short} {} #{id}", sv(input, "kind"))
+        }
+        _ => fmt_args_generic(short, input),
+    }
+}
+
+fn fmt_hyperhive_remind(short: &str, input: &Value) -> String {
+    let when = if let Some(s) = input.get("delay_seconds").and_then(Value::as_u64) {
+        if s < 60 {
+            format!("+{s}s")
+        } else if s < 3_600 {
+            format!("+{}m", s / 60)
+        } else {
+            #[allow(clippy::cast_precision_loss)]
+            let h_f = s as f64 / 3_600.0;
+            format!("+{h_f:.1}h")
+        }
+    } else if let Some(ts) = input.get("at_unix_timestamp").and_then(Value::as_u64) {
+        let h = (ts % 86_400) / 3_600;
+        let m = (ts % 3_600) / 60;
+        format!("at {h:02}:{m:02}Z")
+    } else {
+        String::new()
+    };
+    let msg_raw = input
+        .get("message")
+        .or_else(|| input.get("file_path"))
+        .and_then(Value::as_str)
+        .unwrap_or("");
+    let msg = trim_str(&msg_raw.replace(char::is_whitespace, " "), 60);
+    let when_part = if when.is_empty() {
+        String::new()
+    } else {
+        format!(" {when}")
+    };
+    let msg_part = if msg.is_empty() {
+        String::new()
+    } else {
+        format!(" \"{msg}\"")
+    };
+    format!("{short}{when_part}{msg_part}")
+}
+
+fn fmt_hyperhive_edit_schedule(short: &str, input: &Value) -> String {
+    let id = input
+        .get("id")
+        .and_then(Value::as_u64)
+        .map_or_else(|| "?".to_owned(), |n| n.to_string());
+    let mut parts = vec![format!("#{id}")];
+    if input.get("body").is_some() {
+        parts.push("body".to_owned());
+    }
+    if input.get("interval_seconds").is_some() {
+        parts.push("interval".to_owned());
+    }
+    if input.get("next_fire_at_unix").is_some() {
+        parts.push("next".to_owned());
+    }
+    if let Some(a) = input.get("targets_add").and_then(Value::as_array)
+        && !a.is_empty()
+    {
+        parts.push(format!("+{} tgt", a.len()));
+    }
+    if let Some(r) = input.get("targets_remove").and_then(Value::as_array)
+        && !r.is_empty()
+    {
+        parts.push(format!("-{} tgt", r.len()));
+    }
+    format!("{short} {}", parts.join(" · "))
+}
+
+/// Schedule-management hyperhive tools (list/cancel/fire/edit/request).
+fn fmt_hyperhive_schedule_tool(name: &str, short: &str, input: &Value) -> String {
+    match name {
         "mcp__hyperhive__request_update_meta_inputs" => {
             let ins = match input.get("inputs").and_then(Value::as_array) {
                 Some(arr) if !arr.is_empty() => {
@@ -464,33 +561,7 @@ fn fmt_tool_use(name: &str, input: &Value) -> String {
                 .map_or_else(|| "?".to_owned(), |n| n.to_string());
             format!("{short} #{id}")
         }
-        "mcp__hyperhive__edit_schedule" => {
-            let id = input
-                .get("id")
-                .and_then(Value::as_u64)
-                .map_or_else(|| "?".to_owned(), |n| n.to_string());
-            let mut parts = vec![format!("#{id}")];
-            if input.get("body").is_some() {
-                parts.push("body".to_owned());
-            }
-            if input.get("interval_seconds").is_some() {
-                parts.push("interval".to_owned());
-            }
-            if input.get("next_fire_at_unix").is_some() {
-                parts.push("next".to_owned());
-            }
-            if let Some(a) = input.get("targets_add").and_then(Value::as_array)
-                && !a.is_empty()
-            {
-                parts.push(format!("+{} tgt", a.len()));
-            }
-            if let Some(r) = input.get("targets_remove").and_then(Value::as_array)
-                && !r.is_empty()
-            {
-                parts.push(format!("-{} tgt", r.len()));
-            }
-            format!("{short} {}", parts.join(" · "))
-        }
+        "mcp__hyperhive__edit_schedule" => fmt_hyperhive_edit_schedule(short, input),
         "mcp__hyperhive__request_schedule_prompt" => {
             let tgts = match input.get("targets").and_then(Value::as_array) {
                 Some(arr) => arr
@@ -518,6 +589,13 @@ fn fmt_tool_use(name: &str, input: &Value) -> String {
                 .unwrap_or_default();
             format!("{short} → {tgts} at {when}{recur}")
         }
+        _ => fmt_args_generic(short, input),
+    }
+}
+
+/// `mcp__bash__*` tools.
+fn fmt_bash_tool(name: &str, short: &str, input: &Value) -> String {
+    match name {
         "mcp__bash__run" => {
             let cmd = sv(input, "cmd");
             let first = cmd.lines().next().unwrap_or("").trim().to_owned();
@@ -539,30 +617,13 @@ fn fmt_tool_use(name: &str, input: &Value) -> String {
             };
             format!("{short} {}{force}", sv(input, "id"))
         }
-        "mcp__hyperhive__set_status" => {
-            format!("{short} \"{}\"", trim_str(&sv(input, "text"), 60))
-        }
-        "mcp__hyperhive__get_loose_ends" => {
-            let agent = input
-                .get("agent")
-                .and_then(Value::as_str)
-                .map_or_else(|| "()".to_owned(), |a| format!(" [{a}]"));
-            format!("{short}{agent}")
-        }
-        "mcp__hyperhive__get_agent_meta" => {
-            let name_part = input
-                .get("name")
-                .and_then(Value::as_str)
-                .map_or_else(|| "()".to_owned(), |n| format!(" {n}"));
-            format!("{short}{name_part}")
-        }
-        "mcp__hyperhive__cancel_loose_end" => {
-            let id = input
-                .get("id")
-                .and_then(Value::as_u64)
-                .map_or_else(|| "?".to_owned(), |n| n.to_string());
-            format!("{short} {} #{id}", sv(input, "kind"))
-        }
+        _ => fmt_args_generic(short, input),
+    }
+}
+
+/// `mcp__matrix__*` tools.
+fn fmt_matrix_tool(name: &str, short: &str, input: &Value) -> String {
+    match name {
         "mcp__matrix__read_room" => {
             let limit = input
                 .get("limit")
@@ -584,20 +645,18 @@ fn fmt_tool_use(name: &str, input: &Value) -> String {
             fmt_user(&sv(input, "user_id")),
             json_str(&trim_str(&sv(input, "body"), 50))
         ),
-        "mcp__matrix__send_reaction" => {
-            format!(
-                "{short} {} {}",
-                fmt_room(&sv(input, "room")),
-                sv(input, "key")
-            )
-        }
+        "mcp__matrix__send_reaction" => format!(
+            "{short} {} {}",
+            fmt_room(&sv(input, "room")),
+            sv(input, "key")
+        ),
         "mcp__matrix__open_dm" => format!("{short} {}", fmt_user(&sv(input, "user_id"))),
         "mcp__matrix__invite_user" => format!(
             "{short} {} → {}",
             fmt_user(&sv(input, "user_id")),
             fmt_room(&sv(input, "room"))
         ),
-        _ => fmt_args_generic(&short, input),
+        _ => fmt_args_generic(short, input),
     }
 }
 
@@ -671,9 +730,10 @@ fn fmt_tok(n: u64) -> String {
 /// Shorten a matrix room id/alias for display.
 fn fmt_room(r: &str) -> String {
     if r.starts_with('!') {
-        // Room id: keep only the local part before the colon (up to 8 chars).
-        let end = r.find(':').unwrap_or(r.len()).min(9);
-        r[..end].to_owned()
+        // Room id: keep only the local part before the colon (up to 9 chars).
+        // Use chars().take() so we never slice on a non-ASCII byte boundary.
+        let colon = r.find(':').unwrap_or(r.len());
+        r.chars().take(colon.min(9)).collect()
     } else if r.starts_with('#') {
         // Alias: keep `#name` part before the server.
         r.split(':').next().unwrap_or(r).to_owned()
diff --git a/hive-agent/src/web_ui/stream.rs b/hive-agent/src/web_ui/stream.rs
index 24f855a9..3c881cd4 100644
--- a/hive-agent/src/web_ui/stream.rs
+++ b/hive-agent/src/web_ui/stream.rs
@@ -84,7 +84,7 @@ pub(super) async fn events_stream(
         // (`_icon`, `_summary`, `_category`) so the frontend doesn't need to
         // duplicate the dispatch logic. The DB stores raw events; enrichment
         // is applied here so both the live tail and the history endpoint
-        // deliver the same shape (see `events_history` below).
+        // deliver the same shape (see `events_history` above).
         if let crate::events::LiveEvent::Stream(ref mut v) = ev.event {
             crate::stream_enrich::enrich(v);
         }