Claude Code / AI Coding Tools
Claude Code WebSearch fails with 'deepseek-reasoner does not support this tool_choice' error
User wants to use Claude Code WebSearch tool but encounters a 400 API error when deepseek-reasoner model is used; needs fix to restore search functionality for both Chinese and English queries. Includes evidence for Claude Code troubleshooting demand.
- Category
- AI Coding Tools
- Error signature
deepseek-reasoner does not support this tool_choice- Quick fix
- Compare the failing environment with a known working setup, then change one configuration value at a time.
- Updated
What this error means
deepseek-reasoner does not support this tool_choice is a Claude Code failure pattern reported for developers trying to user wants to use claude code websearch tool but encounters a 400 api error when deepseek-reasoner model is used; needs fix to restore search functionality for both chinese and english queries.. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.
Why this happens
GitHub Issue #58590 on anthropics/claude-code (updated 2026-05-20). Real user report: API Error 400 blocks WebSearch for all queries. Category maps to AI Coding Tools per SKILL.md rules (Claude Code errors → AI Coding Tools). High commercial value as Claude Code is a paid subscription IDE tool.
Common causes
- GitHub Issue #58590 on anthropics/claude-code (updated 2026-05-20). Real user report: API Error 400 blocks WebSearch for all queries. Category maps to AI Coding Tools per SKILL.md rules (Claude Code errors → AI Coding Tools). High commercial value as Claude Code is a paid subscription IDE tool.
Quick fixes
- Confirm the exact error signature matches
deepseek-reasoner does not support this tool_choice. - Check the Claude Code account, local tool state, and provider configuration involved in the failing workflow.
- Compare the failing environment with a known working setup, then change one configuration value at a time.
Platform/tool-specific checks
- Verify the command, editor, extension, or API client that produced the error.
- Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
- Avoid deleting credentials, local model data, or project settings until the failing scope is clear.
Step-by-step troubleshooting
- Capture the exact error message and the command, editor action, or request that triggered it.
- Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
- Review the source evidence below and compare it with your environment.
- Apply one change at a time and rerun the smallest failing action.
- Keep the working fix documented for the team or deployment environment.
How to prevent it
- Keep provider/tool configuration documented.
- Record non-secret diagnostics such as tool version, provider name, model name, and command path.
- Add a lightweight check before CI or production workflows depend on the tool.
Sources checked
Evidence note: GitHub Issue #58590 on anthropics/claude-code (updated 2026-05-20). Real user report: API Error 400 blocks WebSearch for all queries. Category maps to AI Coding Tools per SKILL.md rules (Claude Code errors → AI Coding Tools). High commercial value as Claude Code is a paid subscription IDE tool.
Related errors
- AI Coding Tools
FAQ
What should I check first?
Start with the exact deepseek-reasoner does not support this tool_choice text and the smallest action that reproduces it.
Can I ignore this error?
No. Treat it as a failed Claude Code workflow until the root cause is understood.
Is this guaranteed to have one fix?
No. The imported evidence supports the troubleshooting path above, but tool behavior can vary by account, plan, version, provider, and local configuration.
How do I know the fix worked?
Rerun the same command, editor action, or request. The fix is working when that action completes without deepseek-reasoner does not support this tool_choice.