Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=true, so the mutation and safety profile is covered structurally. The description's one added behavioral fact — that the checklist is created empty — is genuinely useful because it implies items must be added via a separate call, but nothing is said about auth requirements or side effects.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.