Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Without annotations, the description must disclose behavior. 'Reset to initial state' implies discarding current session progress, but it does not clarify side effects (e.g., whether data is permanently lost) or assume an active session. This is minimally adequate but lacks depth.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.