Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed-world scope, so the safety profile is covered. The description adds genuine domain context — that the result is a batch plus its items and that item status READY implies a slideshowId — but says nothing about item counts, pagination, or behavior on an unknown batchId.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.