Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is established. The description adds valuable behavioral context by explaining the conditional returns (authenticated:true with empty pending[] vs. connect_url and per-install URLs), which goes beyond what annotations provide.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.