Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already provide readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is clear. The description adds value by specifying that the response includes the folder and its lists, but does not elaborate on any other behavioral traits like pagination or data volume.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.