The other three building blocks shape and bound the output.
Context gives the background the AI needs. "The apartment is recently renovated, in a quiet neighborhood, and close to good schools." The AI can't read your mind or your files — context is how you hand it the facts.
Format says how you want the output shaped. "Give it to me as three short paragraphs, no bullet points."
Constraints set the boundaries. "Keep it under 120 words and avoid clichés like 'dream home.'" Telling the AI what not to do is as useful as telling it what to do.
A Concrete Example
Put all five blocks together: "You are a friendly marketing copywriter (role). Write a short email inviting existing customers to our new budgeting app launch (task). The app helps first-time savers build a budget in minutes (context). Format it as two short paragraphs plus a call-to-action button labeled 'Get Early Access' (format). Keep it under 150 words and don't use an exclamation mark in every sentence (constraints)." That prompt leaves almost nothing to chance.
Context feeds it, format shapes it, constraints keep it in bounds.