[BUG] Content filtering policy blocks legitimate license text output

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?

Bug Report

### Description

Claude Code's content filtering policy blocks legitimate output when working with
open-source license files (MIT License, EPICS Open License). Both Write tool calls
and text responses containing standard license text are rejected with HTTP 400.

### Steps to Reproduce

1. Ask Claude Code to create a standard MIT LICENSE file for a project
2. Claude writes the file successfully, but the response after the tool call is blocked
3. Subsequent responses that reference or display the license text are also blocked

### Error Message

API Error: 400 {"type":"error","error":{"type":"invalid_request_error",
"message":"Output blocked by content filtering policy"},
"request_id":"req_011CYvXmJx15CuNxXK3axd22"}

### Affected Request IDs

• req_011CYvXmJx15CuNxXK3axd22 (Write tool response blocked)
• req_011CYvXsekHbmxYWFBQb5RbL (Read tool response blocked)

### Context

• Working on an open-source Rust project that ports several C EPICS libraries
• Task: create MIT LICENSE file and investigate third-party license compatibility
• The Write tool successfully wrote the file, but the assistant's response after

the tool call was blocked by the content filter

• A follow-up Read of the same file was also blocked
• Content was a standard MIT License template — no sensitive or harmful material

### Expected Behavior

Standard open-source license text (MIT, BSD, Apache, etc.) should not trigger
content filtering. License file creation is a routine software engineering task.

### Environment

• Claude Code CLI
• Model: claude-opus-4-6
• Platform: macOS (Darwin 25.3.0)

What Should Happen?

Writing and reading standard open-source license files (MIT, BSD, Apache, EPICS Open License, etc.)
should not be blocked by the content filtering policy. These are routine software engineering tasks
that Claude Code should handle without interruption.

Error Messages/Logs

Steps to Reproduce

1. Open Claude Code in a project directory
2. Ask Claude to create a LICENSE file: "create an MIT LICENSE file"
3. Claude calls the Write tool — the file is written successfully
4. The response after the Write tool call is blocked with:

API Error: 400 "Output blocked by content filtering policy"

1. Ask Claude to read the LICENSE file it just created
2. The Read tool response is also blocked with the same error

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.72

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_