Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a search tool with six parameters, rich annotations, and an output schema, the description covers purpose, scope, platform, and return values. It explains the default upcoming-only behavior and the key output fields. The existence of an output schema means return structure need not be detailed here, making this fully complete.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.