Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the safety profile is known. The description adds valuable behavioral context by specifying conditional outputs: authenticated:true with empty pending[] when all connected, and connect_url when credentials are missing. This goes beyond annotations and helps set expectations without repeating them.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.