where did the knife come from

A developer compares prompt engineering to writing a clear how-to, noting that models need explicit context—like a knife for a sandwich—to succeed. The developer describes a three-phase journey from one-liner prompts to treating prompts as environments that supply all necessary information.

In third grade I had to write a how-to for making a peanut butter and jelly sandwich. I thought I'd nailed it. Four steps: My teacher read it, looked up, and asked one question: Where did the knife come from? I had the vision. I'd skipped the environment. The knife was real in my head I'd seen it in the drawer that morning so I assumed it was real on the page. It wasn't. When I started taking prompt engineering seriously last year, I realized I was repeating the third-grade mistake. The arc was familiar enough that I think most people walk it. Phase one: the one-liner. Single sentence. Expect the model to read your mind. When it fails, fight with it in the next turn instead of fixing the prompt. Phase two: the notebook. Start saving prompts that worked. Notice that consistency matters. Notice that some prompts are doing work the model can't actually do without more setup around it. Phase three: the environment. Realize the prompt isn't an instruction. It's a room. The model can only use what's in the room. If the knife isn't in the room, the sandwich doesn't get made, no matter how clearly you described the spreading motion. Three things stacked on top of each other: There's no magic word. There's no clever phrasing trick. Prompt engineering is the same skill as writing a good bug report or a clear design doc: assume the reader doesn't have your context, then put the context in the document.