diff --git a/docs/4-implementation/web-ui/agent-page.md b/docs/4-implementation/web-ui/agent-page.md
index ac74d977e..7b93b4df9 100644
--- a/docs/4-implementation/web-ui/agent-page.md
+++ b/docs/4-implementation/web-ui/agent-page.md
@@ -161,7 +161,9 @@ from the harness-local store (same effect as `cancel_loose_end(kind:
 "todo")`, just from the web UI instead of the agent's own tool calls).
 If the todo store errors or doesn't answer for any id, the endpoint returns
 500 naming how many ids failed, and the panel shows `failed: …` instead of
-`✓ marked done`.
+`✓ marked done`. The calls share one 3-second deadline, so a stalled store
+gets its 500 after about 3 seconds however many ids you check; ids not
+answered by then count as failed. A request with more than 200 ids gets a 400.
 
 ## Live view