Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds value beyond those annotations by explaining the two concrete return-state behaviors: fully connected returns authenticated:true with empty pending[], and missing credentials returns connect_url plus per-install URLs.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.