Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, and non-destructive traits. The description adds value by specifying the two behavioral states: returns authenticated:true with empty pending[] when connected, or connect_url when credentials are missing. This goes beyond the annotations, though it does not cover partial connection states or potential errors.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.