Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity, annotations, parameter schema, and output schema, the description is complete enough to call correctly. It covers purpose, when to use it, the main alternative, pricing, payment-required behavior, and error handling; return-value details are unnecessary because an output schema exists.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.