Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a single-parameter read-only search tool with an output schema present, the description covers the essential behavior and result contents. It doesn't detail match semantics (e.g., substring vs exact, case sensitivity), but those are not critical for a correct call. The tool is simple enough that this description is complete for an agent.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.