Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint: true, so the agent knows this is a safe read. The description adds that it retrieves events in addition to the session, but does not disclose any behaviors like pagination, limits, or error conditions. The read-only nature is consistent with annotations, so no contradiction.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.