Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's modest complexity, fully described parameters, and an existing output schema, the description is complete. It clarifies the aggregation period, the nature of the data returned, and the privacy boundary. There is no obvious missing information an agent would need to decide whether or how to invoke this tool.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.