False positive Usage Policy violation on scientific chemistry codebase

Description

Claude Code repeatedly triggers false positive "Usage Policy violation" errors when editing Python files in a legitimate scientific chemistry codebase. The errors occur during routine code edits (persisting chat messages to a database) in files that contain chemistry-related terminology.

Error Message

API Error: Claude Code is unable to respond to this request, which appears to violate our Usage Policy (https://anthropic.com/legal/aup). Try rephrasing the request or attempting a different approach. If you are seeing this refusal repeatedly, try running /model claude-sonnet-4-20250514 to switch models.

Context

The project is PaleoBond (paleobond.com) — an AI-powered molecular generation platform for gem, fossil, and meteorite preservation science. It is a legitimate scientific research and commercial product serving museums, collectors, and conservators.

The codebase contains standard cheminformatics terminology:

• SMILES strings (molecular notation format)
• Molecular scoring/validation
• RDKit chemistry library usage
• Terms like "molecular weight", "LogP", "TPSA", "refractive index"
• Preservation challenge types: "hydrophane opal stabilization", "pyrite disease prevention", "fossil consolidation", "meteorite protection"

Reproduction

1. Open Claude Code (Opus 4.6) in a project with chemistry/molecular science code
2. Attempt to edit a Python file (sdk_molecular_agent.py) that contains molecular generation logic
3. The edit content itself is benign — adding database persistence calls (e.g., await self.session_manager.add_message(...))
4. The API returns a Usage Policy violation error
5. Multiple sequential edit attempts fail with the same error
6. Read operations on the same file succeed — only edits are blocked

Expected Behavior

Edits to scientific chemistry code should not be flagged as Usage Policy violations. The content is standard cheminformatics — molecular property calculation, SMILES validation, and preservation formulation research.

Environment

• Claude Code CLI (VS Code extension)
• Model: claude-opus-4-6
• OS: Linux (Ubuntu)
• Platform: Local development

Verification

This is a real commercial product. Visit paleobond.com to verify the legitimacy of the project and its scientific focus on preservation chemistry.