[BUG] Web search issue

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?

Web Search("awslabs mcp server S3 npm package setup claude code s3 presign upload")
⎿  Did 1 search in 7s
⎿  Error: InputValidationError: WebFetch failed due to the following issue:
The required parameter prompt is missing

This tool's schema was not sent to the API — it was not in the discovered-tool set derived from message history. Without the schema in your prompt, typed parameters (arrays, numbers, booleans) get emitted as strings and the
client-side parser rejects them. Load the tool first: call ToolSearch with query "select:WebFetch", then retry this call.

What Should Happen?

web search succeeds without errors

Error Messages/Logs

Steps to Reproduce

open claude code
use web search tool

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.86

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_