[BUG] --tools "" does not disable all tools as documented

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?

The docs for --tools state: Use "" to disable all. However, passing --tools "" has no effect and all tools remain available.

What Should Happen?

--tools "" should disable all tools, making Claude unable to use Bash, Read, Edit, Write, etc.

Error Messages/Logs

Steps to Reproduce

  # Expected: no tools available, should refuse to use Edit
  claude -p "Add a comment '# test' to the top of README.md using the Edit tool" --tools ""

  # Actual: uses Read and Edit as if --tools was not passed at all


### Claude Model

Sonnet (default)

### Is this a regression?

I don't know

### Last Working Version

_No response_

### Claude Code Version

2.1.69 (Claude Code)

### Platform

Anthropic API

### Operating System

macOS

### Terminal/Shell

Terminal.app (macOS)

### Additional Information

_No response_