Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With no output schema, the description usefully enumerates the returned measures (likes, comments, reposts, impressions, reach) plus the record scope, and annotations cover the safety profile. Remaining gaps are minor: no time window, no statement about draft ordering or whether drafts with zero performance are included.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.