Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity (3 parameters, external data fetch, output schema exists), the description covers purpose, input, and output. It misses detailing the lookbackDays parameter, but the output schema handles return values. Nearly complete for a read-only, idempotent tool.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.