Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), so the description adds useful operational context: conditional drop-zone availability, multi-file ordering, signed upload_url plus curl generation, and that the file_id only works after the PUT completes. It does not mention authentication or rate limits, but the behavioral lifecycle is well disclosed.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.