Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple single-parameter lookup tool with annotations covering safety and external data, the description covers the key aspects: purpose, scope, return type, and pagination. No output schema exists, but 'returns a list' gives sufficient expectation. A couple more details on the response shape would perfect it, but it's adequate.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.