[BUG] Editing Claude Code Agent tools is not working

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?

When I am trying to edit tools of existing agent

<img width="450" height="260" alt="Image" src="https://github.com/user-attachments/assets/58475716-2ffe-457f-87fc-891abf2ba528" />

Selecting all tools, and pressing continue:

<img width="450" height="260" alt="Image" src="https://github.com/user-attachments/assets/d846f69f-cc4a-4235-8723-e9e2b5be6332" />

In theory this should work, but when I check the agent again, nothing has changed:

<img width="476" height="240" alt="Image" src="https://github.com/user-attachments/assets/628e319c-b31c-4bed-aa0d-18b7f33d6271" />

What Should Happen?

It should update tools once I pressed 'Continue'

Error Messages/Logs

No erros

Steps to Reproduce

1. Create new Agent and set rules
2. Try to change the rules (add new ones)
3. Rules won't be updated

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.76 (Claude Code)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

_No response_