[BUG] Claude says MCP cannot be used in Claude Code on the Web

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?

Whenever I launch the Web version of Claude Code and give it a task that requires MCP, Claude always tells me that it can only use GitHub.

What Should Happen?

MCP should be available on the Web version as well. I don't understand why it says it cannot be used.

Error Messages/Logs

Steps to Reproduce

1. Ask Claude Code to "send a message on Slack."
2. Claude will immediately respond with something like, "MCP is not available. Please configure it correctly! It's not my fault!" lol

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

I don't know

Platform

Other

Operating System

Other

Terminal/Shell

Other

Additional Information

_No response_