Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full burden for behavioral disclosure. '投稿する' (post) implies a write/mutation operation, but the description doesn't mention authentication requirements, rate limits, error conditions, or what happens after posting (e.g., does it return the created comment?). This leaves significant behavioral gaps for an agent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.