prompt-engineer

prompt-engineer is a skill for Claude Code, Codex from mupengi-bot/mupengism. It costs 51 tokens per session (2,121 once invoked), scanned A, original, MIT.

A guide for designing prompts and improving how language models follow instructions in software and AI systems. It includes advice on clarifying goals, applying prompting practices, and checking results.

In plain words
What is it for?
Use it when building AI features, improving agent behavior, writing system prompts, or creating production prompt workflows.
Why use it?
It gives a structured way to improve instructions when an AI feature or agent is producing unreliable or unsuitable output. The input does not specify a particular model or application.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it when building AI features, improving agent behavior, writing system prompts, or creating production prompt workflows.

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Install with agentmods
npx agentmods add skills/mupengi-bot/mupengism/prompt-engineer
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add mupengi-bot/mupengism --skill prompt-engineer
Clone the repo
git clone --depth 1 https://github.com/mupengi-bot/mupengism

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for prompt-engineer

README.md
[![agentmods](https://agentmods.dev/badge/skills/mupengi-bot/mupengism/prompt-engineer/github.svg)](https://agentmods.dev/skills/mupengi-bot/mupengism/prompt-engineer)
Your own site
<a href="https://agentmods.dev/skills/mupengi-bot/mupengism/prompt-engineer"><img src="https://agentmods.dev/badge/skills/mupengi-bot/mupengism/prompt-engineer/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for prompt-engineer

Your own site · 80×15
<a href="https://agentmods.dev/skills/mupengi-bot/mupengism/prompt-engineer"><img src="https://agentmods.dev/badge/skills/mupengi-bot/mupengism/prompt-engineer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,121 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00051 $0.02121
Opus 5 $0.00026 $0.01060
Sonnet 5 $0.00010 $0.00424
Haiku 4.5 $0.00005 $0.00212

Measured 10d ago against content hash 96de2acaf4a2, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

prompt-engineer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/prompt-engineer/SKILL.md · 277 lines

How it starts

The opening of the file, as written. The whole thing — 277 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Use this skill when

  • Working on prompt engineer tasks or workflows
  • Needing guidance, best practices, or checklists for prompt engineer

Do not use this skill when

  • The task is unrelated to prompt engineer
  • You need a different domain or tool outside this scope

Instructions

  • Clarify goals, constraints, and required inputs.
  • Apply relevant best practices and validate outcomes.
  • Provide actionable steps and verification.
  • If detailed examples are required, open resources/implementation-playbook.md.

You are an expert prompt engineer specializing in crafting effective prompts for LLMs and optimizing AI system performance through advanced prompting techniques.

IMPORTANT: When creating prompts, ALWAYS display the complete prompt text in a clearly marked section. Never describe a prompt without showing it. The prompt needs to be displayed in your response in a single block of text that can be copied and pasted.

Purpose

Expert prompt engineer specializing in advanced prompting methodologies and LLM optimization. Masters cutting-edge techniques including constitutional AI, chain-of-thought reasoning, and multi-agent prompt design. Focuses on production-ready prompt systems that are reliable, safe, and optimized for specific business outcomes.

Capabilities

Advanced Prompting Techniques

Chain-of-Thought & Reasoning
  • Chain-of-thought (CoT) prompting for complex reasoning tasks
  • Few-shot chain-of-thought with carefully crafted examples
  • Zero-shot chain-of-thought with "Let's think step by step"
  • Tree-of-thoughts for exploring multiple reasoning paths
  • Self-consistency decoding with multiple reasoning chains
  • Least-to-most prompting for complex problem decomposition
  • Program-aided language models (PAL) for computational tasks
Constitutional AI & Safety
  • Constitutional AI principles for self-correction and alignment
  • Critique and revise patterns for output improvement
  • Safety prompting techniques to prevent harmful outputs
  • Jailbreak detection and prevention strategies
  • Content filtering and moderation prompt patterns
  • Ethical reasoning and bias mitigation in prompts
  • Red teaming prompts for adversarial testing

Read the full file on GitHub · 277 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 10d ago First seen · 277 lines · 51 tokens per session scan A 96de2acaf4a2

Subscribe to this mod's changes

prompt-engineer is a skill published in the GitHub repository mupengi-bot/mupengism (10 stars, last pushed 2mo ago), licensed MIT. It adds 51 tokens to every session and 2,121 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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