Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With no output schema and zero parameters, the description should clarify what 'summary counts' includes (e.g., grouped by status, source, or overall total). The ambiguity could cause an agent to misunderstand the return format. However, for a simple no-parameter summary tool, it provides enough to differentiate from list/get tools, so it is minimally adequate.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.