[Desktop] select_tools reloads built-in Agent and causes duplicate tool name HTTP 400 #4717

Summary

Loading the built-in Agent / AgentSwarm tools through select_tools makes the next model request fail with HTTP 400 because Agent is present in both request-level tools and message-level tools. The session then becomes unusable: Continue and resuming it reproduce the same failure.

Environment

• Kimi Code Desktop 1.3.1
• Windows
• Model: kimi-code/k3.1-pro
• Long-running restored session

Steps to reproduce

1. In a session where the built-in Agent tools are available, invoke:

   {"names":["Agent","AgentSwarm"]}

   through select_tools after the tool set has changed.

2. The tool returns Loaded: Agent, AgentSwarm.

3. On the next model request, the API rejects the request:

   duplicate tool name Agent between request-level tools and message tools at message position 933
   provider.api_error · HTTP 400
   

4. Click Continue, or resume the session and try again. The same error remains at message position 933.

The failing request had 934 messages; position 933 is the final tool-result message produced by select_tools. It appears that loading the tool adds message-level schemas without deduplicating the existing request-level Agent schema.

Expected behavior

Tool loading should deduplicate schemas by name across request-level and message-level definitions, or reject an already-loaded built-in tool locally without poisoning subsequent requests.

Actual behavior

Every later model call is rejected before generation, so the task cannot continue in that session.

Request IDs (2026-11-05, UTC+8)

• 20:52:17 — 10e97fd8743b6e382fb19025f657cc93
• 20:53:26 — 4d2b1aad9d5447d562f8577949d579aa
• 20:59:45 — 912f1cc20b49ac085eed874a78654981

No conversation logs or business code are attached to keep the report sanitized. I can provide a minimal sanitized wire excerpt if needed.