Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover safety (readOnly, idempotent, non-destructive). The description adds valuable behavioral context by specifying it operates on the 'latest version' of the dataset and by enumerating the returned fields (file names, content types, sizes, download URLs). This goes beyond the annotations and informs the agent of the scope.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.