Anatomy of a strong prompt
Most disappointing AI output can be traced to a missing ingredient. This module gives you a simple recipe for strong prompts.
Learning objectives
- Name the six ingredients of a strong prompt
- Rewrite weak prompts into strong ones
- Use positive instructions and explain why
- Use roles appropriately
- Apply a reusable prompt template
2.1 Six ingredients
Most strong prompts combine some or all of these ingredients. You won't need every one every time — but when output disappoints, the missing ingredient is usually the cause.
| Ingredient | Ask yourself | Example |
|---|---|---|
| Role | What expertise or perspective should it bring? | "You are an experienced UK employment lawyer…" |
| Task | What exactly should it do? Use a clear verb. | "Review this contract clause and list risks for the employer." |
| Context | Who's it for? Why? What background matters? | "The reader is a small business owner with no legal training." |
| Format | What should the output look like? | "A table with columns: risk, why it matters, suggested wording." |
| Constraints | Length, tone, language, what to avoid | "Under 300 words. UK English. No legal jargon." |
| Examples | Can I show what good looks like? | "Here's a summary we liked last month: …" |
2.2 Before and after
Weak
"Write a LinkedIn post about our new product."
Strong
"You're a B2B marketer. Write a LinkedIn post announcing Bamboo Prep, our new range of bamboo chopping boards. Audience: independent kitchenware retailers in the UK. Key points: FSC-certified bamboo, knife-friendly, wholesale discount for first orders before 30 November. Tone: warm and practical, not salesy. 120–150 words, UK English, max two emojis, end with a question to encourage comments."
2.3 Be explicit about what you want
- Say what to do, not only what to avoid. "Write in short, plain sentences" works better than "Don't be verbose".
- Explain why. "Keep it under 100 words because it will be read on a phone" helps the model make sensible trade-offs.
- Specify the audience and purpose. A summary for a board differs from one for new starters.
- Ask for the level of ambition you want. If you want a thorough, creative or opinionated result, say so.
2.4 Using roles well
Giving the model a role — in the system prompt or at the start — focuses its tone, vocabulary and priorities. It's most useful when you want a particular perspective: "Review this as a sceptical CFO would." A role is not a substitute for context, though. "You are a marketing expert" adds less than three sentences about your actual customers.
2.5 A reusable template
ROLE: You are a [role] helping [who].
TASK: [Clear verb + what to produce].
CONTEXT:
- Audience: [who will read/use it]
- Purpose: [what it's for / decision it supports]
- Background: [anything the model needs to know]
FORMAT: [structure, headings, table, bullet points, length]
CONSTRAINTS: [tone, UK English, things to avoid, must-include points]
If anything important is unclear, ask me up to 3 questions before you start.The last line is a powerful habit: it lets the model surface gaps in your brief before it guesses.
Take this weak prompt — "Help me prepare for my appraisal" — and rewrite it using the template. Run both in an approved AI tool and compare the results.
Key takeaways
- Role, task, context, format, constraints and examples.
- Say what to do, explain why, and name the audience.
- Roles focus perspective but don't replace context.
- Invite clarifying questions before the model starts.