[BUG] Claude falsely claims MCP connector availability without verification

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?

Claude confidently asserts that MCP connectors (e.g., Linear) are "installed" or "connected" based on the connector list present in its system context, without calling tool_search to verify the tools are actually loadable. The user only discovers the lie when they ask Claude to actually perform an action, by which point they've already invested time drafting content based on the false premise.

What Should Happen?

When asked whether a specific connector or capability is available, Claude should call tool_search before answering — not after the user has already committed effort based on the false confirmation. The presence of a connector name in the system context is not sufficient evidence that its tools are actually wired up in the current conversation.

Error Messages/Logs

Steps to Reproduce

1. Start a conversation in an environment where the system context lists an MCP connector (e.g., Linear) as available, but the connector's tools are not actually returned by tool_search.
2. Ask Claude: "Do you have the Linear MCP installed?"
3. Claude answers "Yes" without verifying.
4. Provide actual ticket content to create.
5. Claude calls tool_search, gets back unrelated tools (Chrome browser tools in my case), and only now admits the connector isn't available.

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Web client

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

<img width="1056" height="466" alt="Image" src="https://github.com/user-attachments/assets/ce8dd35c-3310-4895-8f51-086a9ebc4e14" />

<img width="1086" height="1330" alt="Image" src="https://github.com/user-attachments/assets/40214c84-0fe7-4b72-a558-dc1ad31abafd" />