Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations (readOnlyHint, idempotentHint, destructiveHint), the description discloses specific behavioral outputs: 'authenticated:true and empty pending[]' when connected, and 'connect_url for the toolkit and per-install URLs' when credentials are missing. This adds valuable context about response contents.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.