Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple tool with one optional parameter, an output schema, and comprehensive annotations, the description is adequately complete. It clearly states what is returned and the key variable (language). It does not mention edge cases like invalid language codes, but the schema's default and existing annotations make this a minor gap.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.