Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is known. The description adds valuable behavioral context by detailing what is returned in two distinct scenarios (authenticated:true with empty pending[], or connect_url and per-install URLs), providing concrete response semantics beyond the annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.