Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a write tool with six parameters and an output schema, the description covers the core concept, metrics, actions, and authentication. The missing details (e.g., window and threshold_direction) are already documented in the schema, so the description does not need to repeat them. The lack of explicit prerequisites or return-value explanation is acceptable given the output schema.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.