The one line I add to every summary prompt that stopped the generic output

Most of my "summarize this" results used to read like a book jacket. Technically correct, totally useless for actually using the material. The line that changed it: "Tell me what a careful reader would notice that a skim would miss." That's it. Instead of the safe overview, it starts surfacing the buried assumption, the number that doesn't line up with the claim, the section that contradicts an earlier one. Roughly half the time it flags something I'd have missed on my own read. I usually pair it with a second ask: "Now organize those into the three or four points I'd actually lead with if I had to present this." So the first pass finds the substance and the second pass gives me the structure. Works on long PDFs, meeting transcripts, research threads, anything dense. What's the single line in your prompt that does the most heavy lifting?