Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true, idempotentHint=false and openWorldHint=true, so the safety profile is known. The description adds real context beyond that: the post goes live publicly right now and the action cannot be undone, which is the key consequence an agent must weigh before calling.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.