Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, destructiveHint=false, openWorldHint=false and non-idempotence, and the description is consistent with that (it records an aggregate event but invokes no external actions). It adds real value beyond the annotations: the draft requires a promotional disclosure, the agent must verify the destination's current rules, no endorsement should be implied, and no personal/recipient data may be supplied. It stops short of stating permissions or response behavior, but that is partially covered elsewhere.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.