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

A common belief: "AI is smart, so 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

Weak prompt:

How do I write better emails?

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 cold email to sound less pushy and more like a peer reaching out. Keep it under 80 words. Don't use the word "just". [your email here]

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.".

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…".

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.".

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.".

A Reusable Template

[Context] I'm a [role] at a [company type]. The audience is [audience].
[Instruction] [Verb] the following [thing] so that [goal].
[Format] Reply as [shape], [length].
[Constraint] Don't [thing-to-avoid]. Always [thing-to-include].
[Input] <your text / data / question here>