prompt-engineer

An agent skill by Jeffallan, from Jeffallan/claude-skills. Tags: anthropic, documentation, evaluation, generative, strategy.

What it does

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.

Install

With the skills CLI, which installs into Claude Code, Codex, Cursor and other agents:

npx skills add Jeffallan/claude-skills --skill prompt-engineer

Or copy the skill folder into Claude Code's skills directory by hand (~/.claude/skills for every project, or .claude/skills inside one):

git clone --depth 1 https://github.com/Jeffallan/claude-skills
cp -r claude-skills/skills/prompt-engineer ~/.claude/skills/prompt-engineer

Safety box score

Not rated yet. A safety box score grades what a skill and its scripts can reach on the machine of whoever installs it, across eight categories from shell execution to secrets access. Anyone can request one from this page; it is saved for everyone. How the score works.

Source

Repository

Jeffallan/claude-skills (all skills from this repository)

Path

skills/prompt-engineer/SKILL.md

Branch

main

Updated

2026-09-19

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