Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It only states that it gets stats for a domain but does not describe the response format, whether stats are aggregated, time-constrained, or real-time. The short phrase 'visitor/access statistics' adds minimal context beyond the tool name.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.