“Good enough” answer depth is optimal when the page fully satisfies the query’s real need and anything added would only pad, slow, or over-serve. At that point the optimal depth is exactly what satisfies the intent and no more, because chasing depth past full satisfaction costs effort and reader patience without gaining anything. The pivot is fully satisfies, then stop. Optimal is not the most you could say, it is the precise amount that resolves the query, located at the point where more stops helping.
Reaching that point means the searcher’s actual need is met: the core question answered, the real sub-questions resolved, nothing genuine left open. Once a page has done that, additional depth is not additional value. Extra sections the query did not call for, edge cases the searcher will never hit, caveats nobody asked about, all of these add length and friction while answering questions that were not posed. The reader has what they came for, so more content sits between them and the exit rather than improving the page.
This is why both extremes are wrong. “Always go deeper” treats depth as an unbounded good and produces bloated pages that over-serve and bury their own answers, which can read as a worse fit for the intent. “Minimal is always fine” is the opposite error, stopping before the query’s real need is met and leaving genuine gaps a competitor will close. Optimal sits at neither pole: it is the depth that fully satisfies the specific intent, which is more than minimal for a complex query and less than exhaustive for a simple one, decided by the query rather than by a habit.
For your next page, define what fully satisfying this query’s intent actually requires, then build to exactly that and stop. Resist both the urge to keep adding because more feels safer and the urge to cut before the need is met. Find the point where the searcher would leave satisfied with nothing left to ask, and treat that as done, because past full satisfaction every addition costs without returning.