Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a zero-parameter read-only tool, the description is nearly complete: it explains what is counted, the intended use case, and a key edge case (unclaimed agents). Without an output schema, a minor gap is that the exact return structure for claimed agents isn't specified, but the purpose and behavior are still clear enough for an agent to call the tool confidently.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.