Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The tool is simple (one optional boolean parameter) and has an output schema, so the description doesn't need to explain return values. It covers the essential scope (usage, quota, rate limits, billing), mentions cost ('Free'), and is entirely self-contained. The annotations and schema fill any remaining gaps, so no further context is needed.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.