What Makes a Good Prompt?

You've already discovered that AI doesn't "know" things — it predicts the most likely text based on your input. So what you write directly shapes what you get back.

Vague prompt → vague answer. Specific prompt → specific answer.

This chapter breaks down the four parts of a good prompt.

Why Prompts Matter More Than The Model

It's tempting to think: "AI is smart enough – I can just ask anything and it'll figure out what I mean."

The model has no idea who you are, what your job is, what you've already tried, or what kind of answer you actually need. You have to provide that context.

Same Question — Very Different Results

Let's say you're working with this email:

Hey, just wanted to follow up on my last email about our product. Let me know if you're interested!

Weak prompt:

Make this email better: [your email here]

AI's response:

I hope this message finds you well. I wanted to reach out regarding my previous email about our product offering. I would greatly appreciate the opportunity to discuss how our solution might align with your needs. Please don't hesitate to reach out at your convenience.

You'll get a generic list: be clear, use a subject line, proofread. Not useful.

Strong prompt:

I'm a sales rep at a B2B SaaS company. Rewrite this follow-up email so it sounds like a peer checking in, not a pushy salesperson. Keep it under 40 words. Don't use the word "just." [your email here]

AI's response:

Hey, following up on my last note — did you get a chance to look at it? Happy to answer any questions or jump on a quick call if that's easier.

Short, casual, no salesy tone, under the word limit, no "just." The model knew who you are, what tone to hit, and what to avoid — so it hit the target.

Same model. Same AI. Different prompt.

The Four Parts Of A Good Prompt

1. Context — Who You Are And What's Going On

Tell the AI your role, audience, and situation. This helps it choose the right tone, depth, and terminology.

• "I'm a marketing manager at a 50-person B2B startup.";
• "My audience is non-technical small-business owners.";
• "This is for an internal Slack message, not a press release.".

I'm a [role] at a [company type]. The audience is [audience].

2. Instruction — What You Want It To Do

Use a clear verb. Don't hide the action.

• "Rewrite this paragraph…";
• "Summarise the call notes below…";
• "List 5 risks and rank them by likelihood…".

[Verb] the following [thing] so that [goal].

3. Format — What Shape The Answer Should Take

Define structure, length, and layout.

• "Reply as a 3-bullet list, each bullet under 15 words.";
• "Return a markdown table with columns Risk, Likelihood, Mitigation.";
• "One paragraph, no bullets, under 100 words.".

Reply as [shape], [length].

4. Constraint — What To Avoid Or Include

Prevent common mistakes before they happen.

• "Don't use the word 'just'.";
• "Don't invent statistics — say 'unknown' instead.";
• "No emojis. No exclamation marks.".

Don't [thing-to-avoid]. Always [thing-to-include].

A Worked Example

I'm a content marketer at a B2B SaaS startup. The audience is small-business owners with no technical background. Rewrite the following product description so that it's clear and jargon-free. Reply as one paragraph, under 60 words. Don't use technical terms without explaining them. Always include a concrete example.

[Input] <your text / data / question here>