Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a single-parameter, read-only tool, the description covers all necessary operational details: input format, PII handling, output semantics, follow-up action, privacy, and cost. The output schema likely encodes structures, but the description explains the meaning and step-by-step usage, leaving no guesswork.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.