Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple, read-only list tool with a full input schema, an output schema, and rich annotations, the description covers the essential operational details: market coverage, live pricing, per-model granularity, and auth-free access. Nothing critical is missing for an agent to select and invoke the tool correctly.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.