[BUG] getting frequent error as - API Error: 400 due to tool use concurrency issues.

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?

frquent error coming as - API Error: 400 due to tool use concurrency issues., like 3 times in 4 mins. sys restarted, no parallel execution is happening, no tools are hooked to the system, its simple web app building where i am facing the issue.

<img width="2304" height="2054" alt="Image" src="https://github.com/user-attachments/assets/f1fbeafd-36c2-4e78-80d0-1113e7357908" />

What Should Happen?

smooth without error

Error Messages/Logs

API Error: 400 due to tool use concurrency issues.

Steps to Reproduce

prompting

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.19

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_