[BUG] system reminders about `TodoWrite` keep appearing even if it's a disabled tool

[Lyrcaxis]

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?

Sometimes, the model goes about a system reminder that was posted to it about the TodoWrite tool, spending time thinking why this reminder was posted to it despite the fact it doesn't have access to the specific tool.

What Should Happen?

There should not be system reminders for functionality that isn't active.

Error Messages/Logs

Claude's thinking at a seemingly random time-point:

The user didn't send a new message - this is just a system reminder about a TodoWrite tool. I should ignore this since:
1. I don't actually have a TodoWrite tool available
2. It says to never mention it to the user
3. It says to ignore if not applicable - which it isn't, we're just having a fun debugging conversation

I should wait for the user's actual next message.

Steps to Reproduce

1. Disable TodoWrite tool (from either settings.json or via a cli parameter)
2. Begin vibe-coding
3. At some point, the model will get confused by the fact "TodoWrite" was brought up but it doesn't have access to it so it should ignore it and not bring it up to me :p

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

No response

Claude Code Version

2.0.55 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

No response