Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavior: notifications are unread-only and the upstream caps results at 50, which materially affects how an agent should page.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.