prompt-engineering

Prompt Engineering

Overview

A prompt is an API contract with an AI system. Precision matters. Ambiguous prompts produce inconsistent results; clear prompts produce consistent, predictable behavior.

Core principle: Prompts are executable specifications. Write them like you write tests: with clear inputs, expected behavior, and success criteria.

Iron Law:

TEST YOUR PROMPT WITH AT LEAST 3 DIFFERENT INPUTS BEFORE USING IN PRODUCTION
One input is anecdote. Three is pattern. Ten is confidence.

When to Use

• Writing system prompts for codingbuddy agents
• Creating CLAUDE.md / .cursorrules instructions
• Designing tool descriptions for MCP servers
• Optimizing prompts that produce inconsistent results
• Building prompt chains for multi-step workflows

Prompt Anatomy

Every effective prompt has these components:

┌─────────────────────────────────────────┐
│ ROLE        Who/what is the AI?         │
│ CONTEXT     What situation are we in?   │
│ TASK        What specifically to do?    │
│ CONSTRAINTS What rules must be obeyed?  │
│ FORMAT      How to structure output?    │
│ EXAMPLES    Show, don't just tell       │
└─────────────────────────────────────────┘

Not every prompt needs all components, but most production prompts need most of them.

Prompt Patterns

Pattern 1: Role + Task (Basic)

You are a [specific role].

Your task: [specific action] for [specific context].

Example:

You are a TypeScript code reviewer specializing in security.

Your task: Review the authentication module below for OWASP Top 10 vulnerabilities.
Output a list of findings ordered by severity (Critical → High → Medium → Low).

Pattern 2: Chain-of-Thought (Complex Reasoning)

Force step-by-step reasoning before conclusions:

Before answering, think through:
1. [First consideration]
2. [Second consideration]
3. [Third consideration]

Then provide your conclusion.

Example:

Before suggesting a fix, think through:
1. What is the root cause of this bug?
2. What are the possible fix approaches?
3. What are the trade-offs of each approach?
4. Which approach has the least risk?

Then provide your recommendation with rationale.