Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It usefully discloses that the reply is 'public' and is a 'developer' reply, signaling a public write operation. However, it does not address important behavioral aspects such as whether an existing reply can be overwritten, auth/permission requirements, or response/error behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.