Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's complexity (generating multiple thread variants) and the presence of an output schema, the description covers: input source types, variant hooks, character limit validation, and the non-posting nature. It lacks detail on how the output is structured (handled by output schema) and does not mention the variantCount enum range (but schema covers that). Overall, very solid.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.