Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a one-parameter, read-only statistics tool with no output schema, the description covers the dataset scope, the exact statistics computed, and handling of formatted and non-numeric values. It does not specify the output shape or an all-non-numeric edge case, but these are not critical for selecting and invoking the tool.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.