Right question to ask, however, good readers/professionals do have some sense for this and ability to dig further as needed. On the other hand, books and articles are often over-detailed, with the key stuff buried in the lede or even remaining tacit.

For me, LLMs have often pointed me to answers or given food for thought that even subject matter experts could not. I do not take those answers at face value, but the net result is still better than the search remaining open-ended.