[Bug] Anthropic API Error: Tool result block missing corresponding tool use block

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Bug Description
API Error: 400 messages.5.content.0: unexpected tool_use_id found in advisor_tool_result blocks: srvtoolu_01WNW3RQDq2wFXb9AfbQmzjc. Each advisor_tool_result block
must have a corresponding server_tool_use block before it.

Environment Info

• Platform: darwin
• Terminal: WarpTerminal
• Version: 2.1.169
• Feedback ID: ef5496c0-5052-4541-9c39-e5abd40d467a

Errors

[{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.5.content.0: unexpected `tool_use_id` found in `advisor_tool_result` blocks: srvtoolu_01WNW3RQDq2wFXb9AfbQmzjc. Each `advisor_tool_result` block must have a corresponding `server_tool_use` block before it.\"},\"request_id\":\"req_011Cbt5USpg71qxWSGvvmWug\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:68056)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:51:7694)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-06-09T17:26:32.813Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.5.content.0: unexpected `tool_use_id` found in `advisor_tool_result` blocks: srvtoolu_01WNW3RQDq2wFXb9AfbQmzjc. Each `advisor_tool_result` block must have a corresponding `server_tool_use` block before it.\"},\"request_id\":\"req_011Cbt5ae1YKvwdcfyuapTpd\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:68056)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:51:7694)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-06-09T17:27:56.681Z"}]

What Should Happen?

Should have allowed to continue the session atleast

Error Messages/Logs

API Error: 400 messages.5.content.0: unexpected `tool_use_id` found in `advisor_tool_result` blocks: srvtoolu_01WNW3RQDq2wFXb9AfbQmzjc. Each `advisor_tool_result` block 
  must have a corresponding `server_tool_use` block before it.

Steps to Reproduce

Launch a skill, run advisor, set a goal. Encountered below error. Session is unusable now, doesnt get back even after /exit.

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.170

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Warp

Additional Information

<img width="1447" height="757" alt="Image" src="https://github.com/user-attachments/assets/8a7cad82-fd3d-4822-b662-ed78fd0843f4" />