diff --git a/src/workspaces/officerdev/src/hooks/useChat.ts b/src/workspaces/officerdev/src/hooks/useChat.ts
index fcfd5394..340f6aa8 100644
--- a/src/workspaces/officerdev/src/hooks/useChat.ts
+++ b/src/workspaces/officerdev/src/hooks/useChat.ts
@@ -456,10 +456,32 @@ export function useChat(initialSessionId?: string, initialModel?: string | null,
           toolInput: msg.toolInput,
           toolCallId: msg.toolCallId,
         };
+
+        /*
+          One card per tool call, however many times the harness announces it.
+
+          A tool's input ARRIVES — the SDK emits `tool:start` again as more of it streams in — and this
+          appended every time, so an AskUserQuestion showed up twice: once half-built with two of its three
+          options still missing their descriptions, then again complete. The second carried the answer and
+          the first sat above it forever, unanswerable.
+
+          Keyed on `toolCallId`, and only when there is one: a call without an id cannot be recognised
+          later, and collapsing those on anything else would merge two genuinely different calls.
+        */
+        const upsert = (list: ChatMessage[]): ChatMessage[] => {
+          const at = msg.toolCallId ? list.findIndex((m) => m.role === 'tool' && m.toolCallId === msg.toolCallId) : -1;
+          if (at === -1) return [...list, call];
+          // Keep whatever the earlier event already carried — `output` arrives on `tool:result` and a
+          // late `tool:start` must not erase it.
+          const next = [...list];
+          const existing = next[at]!;
+          if (existing.role !== 'tool') return [...list, call];
+          next[at] = { ...existing, toolName: msg.toolName, toolInput: msg.toolInput };
+          return next;
+        };
+
         const parent = msg.parentToolUseId;
-        setMessages((prev) =>
-          parent ? (withChildren(prev, parent, (kids) => [...kids, call]) ?? [...prev, call]) : [...prev, call],
-        );
+        setMessages((prev) => (parent ? (withChildren(prev, parent, upsert) ?? upsert(prev)) : upsert(prev)));
         break;
       }