Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a signal-only scanner with two parameters, the description covers method, language limits, normalization, severity edge cases, and intended use; an output schema exists, so it need not explain return shape, though it helpfully notes findings come with the rules that fired.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.