Unverified50% confidenceFactExact time
Claude Code v2.1.304 introduced a regression: when an endpoint or gateway rejects tool search, or the gateway does not include it in --tools, every request to Vertex, Bedrock and other providers fails.
1
Sources
50%
Confidence
Medium-term (~90 days)
Relevance
10/20/2026
First Seen
Valid until: 1/18/2027
Sources
Related Entities
Related Claims
UnverifiedThe application matches the keywords 'tool' and 'not supported' in the 400 response body and incorrectly concludes that the model does not support tool calling, thereby stripping tools from subsequent requests and causing browser operations to fail.69% similarUnverifiedTool routing itself can also go wrong, so when classification fails it should fall back to a conservative mode containing all tools rather than directly rejecting the request.68% similarUnverifiedThe most frequent production-level error in tool calling is responding to a tool call with the wrong ID — Claude reports a 400 unexpected tool_use_id error, and OpenAI reports a 400 no tool output found for function call error.66% similarUnverifiedSchema validation for tool calls can only catch structural issues (type errors, missing required fields) and cannot catch semantic errors.66% similarUnverifiedWhen a tool call times out, there are five completely different realities (the request never left the application, the request was rejected, the request was submitted but the response was lost, the webhook was delayed, the submission was duplicated due to a retry), and it cannot be safely retried with only the "tool call failed" label; the correct state should be "unknown outcome" followed by lookup and reconciliation.65% similar
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