Turns a vague agent idea into a reviewable agent spec — the jobs it does, the boundaries it must not cross, and the criteria that decide whether it works. Use this whenever the user talks about building an agent, an assistant, a bot, or an automation, even if they only describe the idea informally and never ask for a spec — a request like "build an agent that handles X" with no written scope is exactly the trigger. Also use it when an existing agent's purpose has drifted and needs restating. Don't use it for choosing tools, models, or architecture, or for writing eval cases, though it produces the raw material for both.
