How to write a good AI prompt: the five-part recipe

A good prompt gives the AI five things: a goal, context, an example, a format and a tone. The assistant only knows what is in the chat, so every part you leave out is a gap it fills with a generic guess.

A vague request, rewritten

Say you need an email asking a supplier about a late order. The vague version:

Write an email about my late order.

You will get a polite, generic email with made-up details. Now the same request with the recipe:

Write a short email to our coffee bean supplier asking where our order is.

Context: I'm Sam, owner of a small online coffee shop. Order #4521 (20 bags of Colombian beans) was due on October 14 and has not arrived. We have a weekend sale coming up. Use only these facts.

Format: a subject line, then under 80 words.

Tone: firm but friendly. Ask for a delivery date by Friday and don't threaten to cancel.

The second prompt returns an email you can send after a quick read. It has the right order number, the deadline and the right length, because you supplied them.

What each part does

• Goal: what you want made, stated first. "Write a short email asking where our order is."
• Context: who you are, who it's for, and the facts the AI must use. If you leave out a number, it may invent one.
• Example: optional. Paste a past email you liked and the AI copies its style. We skipped it here.
• Format: the shape of the answer, such as a subject line plus a word count.
• Tone: how it should sound: friendly, formal, plain.

Two extras help too. Start with a role ("You are an experienced purchasing manager") to shape what the AI pays attention to. Add limits, like "under 80 words" or "don't threaten to cancel", to keep it on target.

Common mistake

Leaving out the facts. If the reply is generic or contains invented details, the context is missing. Put the names, numbers and dates in the prompt and add "Use only these facts."

Saying "try again". When a draft misses, don't repeat the request. Say what is wrong: "Too stiff. Write it like a message to someone we've worked with for years." Specific feedback gets a specific fix.

Takeaway

Before you send a prompt, check that it has a goal, the facts, a shape and a tone. If a reply disappoints, the missing part is usually the reason.