Prompting formula

The CO-STAR formula

Context, Objective, Style, Tone, Audience, Response — the workhorse formula for production prompts.

Skeleton

Context: {situation}
Objective: {goal}
Style: {style}
Tone: {tone}
Audience: {who}
Response: {exact format}

When to use it

Any LLM task where business context matters; default for the Master Engineer.

How to apply it without breaking it

  1. Fill every slot. A formula with a missing slot silently degrades into a generic prompt — the model will fill the gap with its own assumptions.
  2. Keep the ordering. Structure carries meaning; moving the output contract to the front of a long prompt is the most common reason a good formula fails.
  3. Pin the output shape explicitly (format, length, delimiters) rather than describing it in prose.
  4. Test with three inputs: a typical one, an edge case, and one where the correct answer is "insufficient context".

Pairs well with

Other formulas

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