Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already mark it read-only and non-destructive, and the description adds behavioral context: the data source (form_sessions telemetry), scoping to the current team, the look-back window, and the specific funnel/drop-off reports returned. This goes beyond the annotations and clearly sets expectations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.