Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the output schema exists, the description does not need to fully enumerate return values, but it still provides a clear summary. It covers the input source, the statuses, the use case, and authentication. The context is complete for a user deciding to invoke this tool among many siblings.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.