For agents, on top of README.md, which they read first.

• SYSTEM and tools() are behaviour. A change to either changes what every model writes. Rerun tools/eval and update LLM_MODEL if the winner moves.
• The parser repairs one thing only: arguments encoded as JSON twice (granite did this, measured 2026-10-02). Do not add guesses for missing fields, renamed fields or extra fields. A model that needs them is a model the eval should fail.
• Prices in models.rs are copied from Cloudflare's pricing page with the date. When they change, change them there; the Worker prefers the neurons the reply reports and uses the list only for the worst case and as a fallback.