[BUG] API 400 Error due to automatic connection of browser-use MCP server triggered by Cowork settings

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?

When the Cowork (web search/scheduled tasks) feature is enabled, the app installs browser-use into ~/.browser-use-env/. The Code mode (sidebar) in the Claude Desktop app automatically connects to this as an MCP server every time it starts. However, because the tool schema of the browser-use package contains oneOf/anyOf, the Anthropic API throws a 400 error and halts. Even if the user sets the Cowork setting to false, the app processes its own routine first, causing the setting to revert upon restarting the app and resulting in an endless error loop.

What Should Happen?

Claude Code should start normally without crashing due to an MCP server with an incompatible tool schema format.

Error Messages/Logs

API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"tools.19.custom.input_schema: input_schema does not support oneOf, allOf, or anyOf at the top level"}

Steps to Reproduce

Enable the Cowork feature in the Claude Desktop app (v1.1.8629).

The app automatically installs browser-use into ~/.browser-use-env/.

Restart the desktop app and open Code (sidebar), which triggers the error.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

v2.1.51 (Built-in with Desktop app)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

As a workaround, renaming the environment directory from the terminal using mv ~/.browser-use-env ~/.browser-use-env.bak resolves the issue and allows the app to start.