[BUG] /context reports incorrect token counts per mcp tool

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?

/context reports about 600 tokens used for every single tool from added mcp servers, whereas one tool only adds on the order of 100-200 tokens in reality
It looks like it incorrectly counts every single tool token usage one by one, overcounting the shared tools system prelude token by N times, where N is the number of tools

What Should Happen?

/context reports correct token counts for mcp tools

Error Messages/Logs

Steps to Reproduce

Add an mcp server(s) with more than 1 tool overall

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.0.14

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_