Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a low-complexity, one-parameter tool with no annotations and no output schema, the description is fairly complete: it identifies the dataset, the column type, the returned statistics, and data-cleaning behavior. It lacks an explicit output shape or error semantics, but these are not critical for such a simple tool and can be inferred.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.