Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given that an output schema exists, the description need not cover return values. It adequately covers sources, modes, access (keyless/free), and caching. However, it could mention the default mode or that results are limited to 50 results (mentioned in schema). Still, it's fairly complete.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.