Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a three-parameter, enum-driven tool with an output schema covering the return shape, the description supplies purpose, platform scope, and the key formatting caveat. It is essentially complete, with minor room for stating the size limit or error behavior, both of which the schema already handles.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.