Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the tool safe (readOnlyHint, idempotentHint, destructiveHint false). The description adds valuable context about response states (authenticated:true with empty pending[] when connected, connect_url and per-install URLs when missing credentials), going beyond the structured metadata.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.