Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's simplicity (one parameter, no output schema), the description covers the main operation and data-handling nuances. However, it omits the output format (e.g., whether it returns an object with keys like count, min, max, etc.) and does not address error conditions or edge cases (e.g., what if the column does not exist). Since there is no output schema, the description should have specified the return shape to be fully complete.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.