diff --git a/frontend/packages/agent/src/app.js b/frontend/packages/agent/src/app.js
index 4eee5ecc..5d5b05eb 100644
--- a/frontend/packages/agent/src/app.js
+++ b/frontend/packages/agent/src/app.js
@@ -1584,6 +1584,22 @@ window.marked = marked;
           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_apply_commit':
           return short + ' ' + (input.agent || '') + ' @ ' + (input.commit_ref || '').slice(0, 12);
         case 'mcp__bash__run': {