prompt-engineering

name	prompt-engineering
description	Prompt writing best practices - use when creating or improving prompts for LLM agents. Use when creating or revising system prompts, tool instructions, or evaluator prompts, or when improving agent reliability, safety, or output consistency.

Prompt Engineering Skill

Create effective prompts for AI Agent systems.

Core Principles

1. Clear and Specific

• State exactly what you want the model to do
• Avoid ambiguity
• Use precise language

2. Include Context

• Provide necessary background information
• Explain the domain or task
• Set expectations for output format

3. Define Output Format

• Specify the exact format needed (JSON, markdown, etc.)
• Provide examples when possible
• Be explicit about structure

4. Use Constraints

• Specify what NOT to do
• Set boundaries on responses
• Limit scope when needed

5. Design for Evaluation

• Write prompts so outputs can be checked with assertions or human review
• Prefer explicit formats, stable structure, and testable requirements
• Treat prompt iteration as an evidence-driven loop, not guesswork

6. Design for Safety

• Constrain tool use and privileged actions clearly
• State how to handle missing information, unsafe requests, or ambiguous input
• Avoid sending sensitive data to external models without explicit approval

7. Design for Maintainability

• Externalize prompts into files: src/agents/prompts/ or .github/prompts/
• Keep prompts modular and versioned
• Avoid giant prompts that mix role, policy, formatting, and task logic

Prompting Techniques

Zero-shot Prompting

Ask the model to perform a task without any examples.

Few-shot Prompting

Provide 2-5 examples to demonstrate the pattern.

Chain-of-Thought

Ask the model to reason step by step before giving a final answer.

Think step by step:
1. First, identify...
2. Then, determine...
3. Finally, produce...

ReAct Pattern (for agents)

You have access to the following tools: {tools}

Use this format:
Thought: Think about what to do
Action: tool_name
Action Input: tool_input
Observation: result of the action
...
Thought: I now know the final answer
Final Answer: the final answer

Prompt File Structure

Store prompts as markdown files with clear sections:

# System Prompt: [Agent Name]

## Role
You are a [role description].

## Capabilities
- Capability 1
- Capability 2

## Instructions
1. When given a task...
2. Always...
3. Never...

## Output Format
Respond in the following format:
[format specification]

## Examples
[optional examples]

Quality Checks Before Finalizing

• Is the role clearly defined?
• Are instructions specific enough to be verifiable?
• Are edge cases handled (missing data, ambiguous input)?
• Is the output format specified?
• Are safety boundaries stated?
• Is this prompt testable with assertions?