Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a two-parameter tool with a full schema and output schema, the description covers the essential context: what is generated, why it is safe, and what format is returned. A minor gap is that it does not state whether generated data is random/deterministic or that fields default to all when omitted, though the schema covers the default.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.