Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations only cover readOnlyHint=false/idempotentHint=false/destructiveHint=false; the description adds substantial behavior beyond that: colony inference, immediate moderator notification, one pending report per target per reporter with rejection of duplicates, and a 10/hour rate limit. It also clarifies that reporting does not change what the reporter sees. That is exactly the kind of side-effect and constraint disclosure annotations cannot carry.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.