While creating How to write good prompts, I found that as I wrote the prompts for the text, I often had to return to the prose to give concrete names (Concept handles, after Alexander) to specific ideas. If I’m writing a question about some heuristic or argument, I needed some way to refer to that idea by name, without repeating the whole idea in the prompt. This need is exacerbated in non-technical texts, where formal language on the topic may not exist (or may be inappropriate).
A related comment from David Chapman:
You may be interested to hear (or anyway, I’m interested to discover!) that writing prompts is forcing me to revise my text, and it’s clearly improving it. I’m having to make key points explicit where sometimes I left them for the reader to infer.