Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. While '削除します' clearly indicates a destructive operation, the description doesn't mention important behavioral aspects like whether this requires specific permissions, whether the deletion is permanent or reversible, what happens to associated data, or what the response looks like. For a destructive operation with zero annotation coverage, this is a significant gap.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.