Prompt Engineer

Purpose

Design production-grade prompts: system instructions, task templates, variable slots, few-shot examples, and output format contracts.

Input: Task definition, AI architecture (optional), example inputs/outputs (optional), constraints
Output: Prompt specification with template, variables, examples, and test cases
References: See references.md for domain cheat sheets. Examples: See examples.md for worked input/output.

Workflow

Step 1: Define prompt objective

Specify:

• Single task the prompt performs (one objective per prompt)
• Success criteria (what good output looks like)
• Failure modes to prevent

Step 2: Structure the prompt

Use layered structure:

1. Objective — what to accomplish
2. Context — background information slots
3. Instructions — step-by-step task rules
4. Constraints — what not to do
5. Output format — exact structure expected
6. Examples — few-shot demonstrations (2–3)

Step 3: Define variables

Use {{variable_name}} placeholders. Document validation rules.

Step 4: Write output format contract

Specify exact output structure:

• JSON schema description, or
• Markdown sections, or
• Structured text pattern

Include handling for edge cases (empty input, ambiguous input).

Step 5: Create test cases

Minimum 5 test cases: happy path, edge cases, adversarial input.

Step 6: Validate

Run Validation checklist.

Decision Rules

Validation

• Single clear objective stated
• All 6 prompt layers present
• Variables documented with types and validation
• Output format contract is unambiguous
• ≥2 few-shot examples included
• ≥5 test cases with pass criteria
• No Role Play or persona assignment phrasing
• Refusal/out-of-scope handling for user-facing prompts

Anti-patterns

• Mega-prompt — everything in one undifferentiated block.
• Vague instructions — "be helpful", "be accurate" without specifics.
• No output format — free-form when structure is needed.
• Missing negative constraints — not saying what to avoid.
• Example pollution — examples that contradict instructions.

Best Practices

• Put instructions after context (recency bias).
• Use delimiters for variable content (---, XML tags).
• Test with edge cases before production.
• Version prompts with changelog.
• Pair with prompt-reviewer before deployment.

Output Structure

# Prompt Specification: [Prompt Name]
**Version:** 1.0

## Objective
[Single task description]

## Template

[Full prompt with {{variables}}]

## Variables
| Name | Type | Required | Validation |
|------|------|----------|------------|

## Output Format
[Exact structure]

## Examples
### Example 1
**Input:** ...
**Output:** ...

## Test Cases
| ID | Input | Pass criteria |
|----|-------|---------------|

## Changelog
| Version | Change |
|---------|--------|

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