Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint and openWorldHint, so safety is covered; the description adds only the HTTP endpoint, which is not behaviorally useful to an agent. Nothing is said about pagination, result ordering, default filtering, or whether disabled rules are included — the details that actually shape a list call.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.