# prompt-engineer

> Claude/Codex skill by [@jeffallan](https://omgskills.com/library/jeffallan/index.md) · 12k stars · Updated 2026-10-30

Writes, refactors, and evaluates prompts for LLMs — generating optimized prompt templates, structured output schemas, evaluation rubrics, and test suites. Use when designing prompts for new LLM applications, refactoring existing prompts for better accuracy or token efficiency, implementing chain-of-thought or few-shot learning, creating system prompts with personas and guardrails, building JSON/function-calling schemas, or developing prompt evaluation frameworks to measure and improve model performance.

Tags: ai-agents, claude, claude-code, claude-marketplace, claude-skills

## Install

```sh
git clone https://github.com/Jeffallan/claude-skills /tmp/claude-skills && ln -s /tmp/claude-skills/skills/prompt-engineer ~/.claude/skills/prompt-engineer
```

## From README

Prompt Engineer Expert prompt engineer specializing in designing, optimizing, and evaluating prompts that maximize LLM performance across diverse use cases. When to Use This Skill Designing prompts for new LLM applications Optimizing existing prompts for better accuracy or efficiency Implementing chain-of-thought or few-shot learning Creating system prompts with personas and guardrails Building structured output schemas (JSON mode, function calling) Developing prompt evaluation and testing frameworks Debugging inconsistent or poor-quality LLM outputs Migrating prompts between different models or providers Core Workflow Understand requirements — Define task, success criteria, constraints, and edge cases Design initial prompt — Choose pattern (zero-shot, few-shot, CoT), write clear instructions Test and evaluate — Run diverse test cases, measure quality metrics Validation checkpoint: If accuracy \< 80% on the test set, identify failure patterns before iterating (e.g., ambiguous...

## Links

- HTML page: https://omgskills.com/library/jeffallan/claude-skills/prompt-engineer/
- GitHub: https://github.com/Jeffallan/claude-skills
- Author: [@jeffallan](https://omgskills.com/library/jeffallan/index.md)

## More from this repo

- [api-designer](https://omgskills.com/library/jeffallan/claude-skills/api-designer/index.md) — Used when designing REST or GraphQL APIs, creating OpenAPI specifications, or planning API architecture.
   - [@jeffallan](https://omgskills.com/library/jeffallan/index.md) · 12k stars
- [architecture-designer](https://omgskills.com/library/jeffallan/claude-skills/architecture-designer/index.md) — Used when designing new high-level system architecture, reviewing existing designs, or making architectural decisions.
   - [@jeffallan](https://omgskills.com/library/jeffallan/index.md) · 12k stars
- [atlassian-mcp](https://omgskills.com/library/jeffallan/claude-skills/atlassian-mcp/index.md) — Integrates with Atlassian products to manage project tracking and documentation via MCP protocol.
   - [@jeffallan](https://omgskills.com/library/jeffallan/index.md) · 12k stars