Why MSX uses a skill file

A prompt should be easy to remember. An API contract should be precise. Those are different jobs, so MSX keeps them separate.

The public prompt points agents at https://msx.dev/skill.md. The skill file then explains the live auth, billing, investigation, polling, and recovery behavior in a format an agent can follow.

Why this matters

Agent clients can have stale memory. A hosted skill file lets MSX update operational instructions when the API changes, without asking users to paste a new wall of text.

The skill file is also where MSX can be explicit about boundaries: start with device auth, ask before Checkout, do not retry quota errors in a loop, and do not invent results when an investigation is thin.