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 useful scope by saying both the session and the database handle are released, but omits idempotency, error behavior for an unknown/expired sessionId, and whether other sessions are affected. Note the mild tension between 'Close' (a state change) and readOnlyHint=true, though this is resource cleanup rather than data mutation, so it is not a true contradiction.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.