[BUG] base64 encoded image returned in tool result is saved in a json file, claude code can not read it directly

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 my MCP tool returns a tool result with both text content and image content, claude code can not read the result directly.

<img width="1174" height="396" alt="Image" src="https://github.com/user-attachments/assets/5aff05c7-180f-4f3e-989c-eb0c10980103" />

What Should Happen?

Claude should read the tool result without using bash tools

Error Messages/Logs

Steps to Reproduce

Ask claude to invoke a mcp tool that will return a tool result with both text content and image content

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.0.1x

Claude Code Version

2.0.69

Platform

Other

Operating System

Other Linux

Terminal/Shell

Other

Additional Information

_No response_