[BUG] API Error 400: "tool_use ids must be unique" when using -p flag with tool-requiring prompts

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 using claude -p (print mode) with prompts that require tool use (like checking if a file exists or running shell commands), the CLI fails with an API error about duplicate tool_use IDs.

Environment

• Claude Code version: 2.1.19
• OS: macOS Darwin 25.2.0
• Shell: zsh

What Should Happen?

Claude should check if the file exists and return the result.

Error Messages/Logs

API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.1.content.1: `tool_use` ids must be unique"},"request_id":"req_011CXRMKYvALAsgksCjT7HoC"}

Steps to Reproduce

## Steps to Reproduce
``bash
claude -p "check package.json exists"
``

## Pattern Observed

• FAILS: Prompts requiring tool use ("check package.json exists", "echo hello")
• WORKS: Pure text responses ("2+2", "say hello", "how many r in strawberry")

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.18

Claude Code Version

2.1.19

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

IntelliJ IDEA terminal

Additional Information

_No response_