Prompt vs skill vs Agent Skill
A prompt is a one-time brief you type or paste into a chat. A skill is a standing brief — role, context, task, constraints, output — that you reuse across chats. An Agent Skill is a folder with a SKILL.md file (a YAML name and description, then Markdown instructions) that agents such as Claude Code load by themselves when a task matches.
PromptCorrectly is a prompt and skill library: 2,904 structured prompts and 495 skills in one format, across 50 fields, plus 36 short courses. Titles are public; full text is on a plan. You take the text to ChatGPT, Claude or Gemini — and on a plan every skill also downloads as an Agent Skill.
The three, side by side
| Thing | File | Who runs it | Example |
|---|---|---|---|
| Prompt | None — you paste it | You, in a chat | “Rewrite this investor update so it is honest about what we missed.” |
| Skill | A .md brief | You — paste it once as standing instructions | A staff-engineer code reviewer you keep in a Claude Project or a custom GPT |
| Agent Skill | name/SKILL.md (+ optional files) | The agent, when its description matches the task | The same reviewer, loaded by Claude Code whenever you ask it to review a diff |
A skill and an Agent Skill can be the same text. The difference is who decides to use it: you, or the agent.
What “skill library” means in 2026
Two different things share the name. Human prompt-and-skill libraries — like this one — are briefs you read, fill in and paste into ChatGPT, Claude or Gemini. Agent-skill directories index public SKILL.md repositories that coding agents install.
If you want a directory of other people's GitHub skills, an agent-skill index is the better fit. If you want a brief you can read before you use it, fill in, and reuse — and also install as an Agent Skill — that is this library. See also what a skill library is.
Use a PromptCorrectly skill as an Agent Skill
- Open a skill in the skills library.
- On a plan, press Agent Skill (SKILL.md). The file already has the front-matter: a kebab-case
nameand adescriptionthat says when to load it. - Save it as
.claude/skills/<name>/SKILL.mdin a project — or in~/.claude/skills/for every project. - Start Claude Code. It reads the descriptions and loads the skill when your task matches it. Other agents that support the Agent Skills format have their own folder; check their docs.
- Prompts work too: download the .md, or paste it into custom instructions, a Claude Project or a Gemini Gem.
Skills from the library
- Agent Skill AuthorWrites an installable Agent Skill (agentskills.io / Claude Code / Codex CLI) from a messy capability request. Use when a paste-prompt should become a standing specialist.Plan
- Context Engineering BudgetAudits everything entering a model window and cuts it to a budget. Use when a prompt, agent, or prompt chain feels smart in isolation and sloppy in production.Plan
- MCP Server BriefWrites a design brief for a Model Context Protocol server: tools, resources, prompts, permissions, and what must never be exposed. Use before anyone 'just adds MCP'.Plan
- Prompt Debugging SpecialistDiagnose why prompts produce poor outputs and systematically fix them.Free account
- System Prompt EngineerBuild bulletproof system prompts for AI assistants, chatbots, and agents with injection resistance.Plan
Free: every title and opening lines, 274 full prompts (132 without an account), a starter skill per shelf with a free account, and the free courses. On a plan (Library or Pro): every full text, .md downloads and the Agent Skill export. See the plans.
Questions
What is a prompt library?
A catalog of written briefs you paste into an AI chat. A good one uses one structure everywhere, so you can read what a prompt will do before you use it. PromptCorrectly writes every prompt as Role, Context, Task, Constraints and Output.
What is a skill library?
A set of reusable instructions rather than one-off requests. On PromptCorrectly a skill is a standing brief you keep in your AI as custom instructions; an Agent Skill is the same idea packaged as a SKILL.md file that an agent loads by itself.
What is SKILL.md?
The file at the heart of an Agent Skill: YAML front-matter with a name and a description, followed by Markdown instructions. Agents such as Claude Code read the descriptions and load the skill when a task matches. Longer reference material can sit in extra files next to it.
Is PromptCorrectly an Agent Skills directory?
No. It is a library of briefs written for it, in one format, that you read, fill in and reuse. Every skill can be downloaded as a SKILL.md on a plan, but it does not index other people’s GitHub skill repositories.
Do I need an API key?
No. Prompts and skills are text you take to the AI you already use. The Studio’s test runs need a free account, not a key.
What is free?
Every title and the opening lines of every item, a free prompt set, a starter skill per shelf with a free account, the free courses and a monthly allowance of Studio test runs. Full texts, downloads and Agent Skill exports are on a plan.