Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of disclosing behavior. It only says 'Manage Antigravity sessions,' which does not reveal whether actions are read-only, destructive (e.g., 'clear' likely resets or deletes), or how switching works. No side effects, permissions, or state changes are mentioned, leaving the agent blind to the tool's operational implications.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.