Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Without annotations, the description carries full responsibility for disclosing behavioral traits. It only explains what a placement is, not whether the deletion is permanent, reversible, requires special permissions, or affects associated data. It adds minimal behavioral context beyond the name.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.