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. While '取得します' (retrieves) implies a read-only operation, the description doesn't mention authentication requirements, rate limits, error conditions, or what format the reminder notification settings are returned in. For a tool with zero annotation coverage, this is insufficient.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.