Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the full burden of behavioral disclosure. It fails to mention key details such as output format (e.g., ISO 8601 string), timezone handling beyond defaults, or supported timestamp range. This is insufficient for the agent to anticipate the tool's behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.