Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a 3-parameter tool with full schema coverage, an output schema, and rich annotations, the description covers purpose, behavior, cost, and prerequisites. It gives the agent everything it needs to decide to invoke and execute correctly, and the content type list in the schema covers the remaining specifics.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.