Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Adds substantial behavior beyond the annotations: reply timing (Central Time business hours, usually within a few hours), rate limiting, the point-in-time nature of answers, and the warning that agent sessions end so polling alone can strand an answer. This is exactly the operational context annotations can't convey.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.