Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety and side-effect profile is fully covered. The description adds one useful behavioral fact beyond that — every item comes with its URL — but says nothing about result size, ordering, or whether the list is exhaustive.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.