AI Agent Skills Marketplaces: A Seller’s Guide to Buying, Evaluating and Selling Skills

 

By Zaheer | Updated 9 October 2026

Disclosure: I sell skills on Agensi, so I have a commercial interest in the marketplace discussed here. I have tried to keep this guide factual. Prices, fees and catalog sizes change, so check the linked pages for current terms before you buy or sell.

If you use Claude Code, Cursor, Codex or Copilot every day, you will recognise the problem: the same workflow, prompted from scratch, again and again. Or you lose an hour searching GitHub for a SKILL.md that works and doesn't carry a security risk. This guide explains what agent skills are, where to get them, how to judge one before installing it, and what selling one involved from my side.

What is an AI agent skill?

A skill is a reusable package of instructions, with optional scripts, templates and reference files, that teaches an AI agent how to handle a specific kind of task. You write it once and the agent loads it whenever the task calls for it.

Every skill starts with a file named SKILL.md. Under the open Agent Skills specification (agentskills.io), the file begins with frontmatter containing a name (lowercase letters, numbers and hyphens, up to 64 characters) and a description (up to 1,024 characters) that should say both what the skill does and when to use it. The body below holds the step-by-step instructions. A typical skill folder looks like this:

  • SKILL.md: required
  • scripts/: optional executable code
  • references/: optional documents loaded only when needed
  • assets/: optional templates and static files

Why skills don't bloat your context

Skills use what is called progressive disclosure. At startup, the agent reads only each skill's name and description, which is a small amount of text. When your request matches a description, the agent loads the full SKILL.md. Bundled files are opened only if the task needs them, and when a script runs, its output enters the conversation rather than its source code. That is why you can install many skills without filling the context window the way one huge saved prompt would.

The practical lesson is that the description decides whether a skill ever triggers. A vague description means the skill sits unused. I check this first when I evaluate any skill, mine included.

One format, many tools

Because the format is an open standard, a single SKILL.md can work across tools that support it, including Claude Code, Codex CLI, Cursor, Gemini CLI and GitHub Copilot. Each tool uses its own folder for skills. For example, Claude Code reads personal skills from ~/.claude/skills/ and project skills from .claude/skills/. Check your tool's documentation for its exact path.

Where to get skills: three models

ModelWhat you getWhat you give up
Free public directories and GitHub reposHuge choice at no costNo vetting, no support, quality varies widely
Paid marketplaces such as AgensiReview before listing, a security scan, an accountable sellerA few dollars per skill; a young market where quality still varies
Vendor channelsOfficial skills from the tool makers (for example, Anthropic's document skills for Word, Excel, PowerPoint and PDF)Limited to what the vendor chooses to publish

The most common mistake is treating these as the same thing. "Free and public" does not mean "verified", and "paid" does not automatically mean "good".

How I decide between free and paid

For generic, well-documented jobs such as code review, git workflows or standard document handling, free and official skills usually cover you. Paying for a generic skill is paying for packaging.

I consider a paid skill when three things are true:

  1. The workflow encodes domain expertise I don't have.
  2. My own trial and error would cost more time than the price.
  3. I can inspect it first: a readable SKILL.md, a clear description and a visible security-scan result.

How to evaluate any skill before installing it

Treat a skill like any third-party software, because that is what it is.

  1. Define the job in one sentence. "Turn a business URL into a landing page" maps to a skill. "Make my agent better" does not.
  2. Read the description for trigger clarity. Does it say when to use the skill, not just what it does?
  3. Check for scripts. Instructions-only skills are simpler to review. Skills with executable scripts are more powerful but need a closer read.
  4. Read the files yourself. Look for network calls, file access or external URL fetching that doesn't match the stated purpose. Fetched content can carry hidden instructions, so a trustworthy skill can still be affected by what it pulls in.
  5. Test the trigger. After installing, give the agent a task that matches the description and confirm the skill actually loads. If it never fires, the description is weak.

This is also where skills have an advantage over opaque prompt products: the logic is plain text you can read before you trust it.

What Agensi is and what it says about itself

Agensi describes itself as a curated marketplace for SKILL.md skills. Based on its own pages at the time of writing:

  • Every submission goes through an 8-point automated security scan, which its seller page says is followed by an AI review and a human check, usually within 24 to 48 hours.
  • Skills are one-time purchases that work with Claude Code, Cursor, Codex CLI, Gemini CLI, Copilot and other agents that read SKILL.md.
  • Skills are discoverable on the store and through an MCP connection, so an agent can search the catalog. Check the site for the current terms of MCP access.
  • The company says it is registered in the Netherlands.

Limits worth knowing

It is a young marketplace, and listing quality varies from skill to skill. An automated scan reduces risk but does not replace reading a skill yourself. Public reviews and catalog figures are limited and change often, which is why I haven't quoted them here.

Selling on Agensi: what the process looked like for me

I have listed several skills, including the Digital Product Sales Booster and the Landing Page Conversion Optimization System. The process was:

  1. Build a skill around one workflow I already knew well. Narrow skills with a clear trigger are easier to write and easier to test.
  2. Submit it and pass the scan and review. Agensi says

Comments

Post a Comment

Popular posts from this blog

How to Write Reusable AI Image Prompts with Variables (5 Templates You Can Copy)

Image
  By Zaheer | Updated 10 October 2026 Disclosure: I sell image prompts on PromptBase, and some links in the last section are referral links. The techniques and templates before that section are free to use and don't need any purchase. The difference between a lucky AI image and a reliable one is usually the prompt. A one-off prompt gets you one picture. A reusable prompt, with a few clearly marked variables, lets you produce a whole series that looks consistent without rewriting anything. This guide explains how a good image prompt is built, how to turn it into a template, and gives you five templates you can copy and adapt for ChatGPT's image generation, Gemini or similar tools. The anatomy of a good image prompt Most weak prompts are short and vague: "a nice photo of a house". Stronger prompts answer the same handful of questions, in this order: Subject: what is the main thing in the picture? Setting: where is it, and what is around it? Style:...
Read more

Competitive Analysis Made Simple: What a Decision-Ready Competitor Report Includes

By Zaheer | Updated 11 October 2026 Disclosure: I created the Market Recon Engine skill mentioned in this post and sell it on Agensi. The guidance before that section works without it.   Every founder ends up doing the same late-night exercise: seven browser tabs, a half-finished spreadsheet, and a gut feeling about where the market has room. It is slow, easy to get wrong, and usually ends with a pile of facts instead of a decision. This post explains what a useful competitive analysis should actually contain, and shows a short sample from a real run of Market Recon Engine , a skill I just listed on Agensi that does this research in one pass. What a decision-ready competitive analysis includes A good analysis isn't a research summary you still have to interpret. It gives you something you can act on. These are the six parts I think matter most. 1. Feature comparison matrix The capabilities that actually move a purchase decision, rather than a padded checklist of every ...
Read more

Why You Can Rank #1 on Google and Still Be Invisible to ChatGPT (AEO Explained)

Image
  By Zaheer | Updated 9 October 2026 Disclosure: I created the AI Conversion Auditors Pack mentioned near the end of this post and sell it on Agensi. Everything before that section is useful without it. Your site can rank #1 on Google and still get zero mentions when someone asks ChatGPT or an AI Overview the exact same question. Traditional SEO gets you found by search engines. AI search visibility, often called AEO (Answer Engine Optimization), is about something different: whether an AI system can extract, trust and cite your content when it writes an answer. Many sites are tuned for one and blind to the other. SEO and AEO: what is actually different? Search engines return a list of links and let the reader choose. AI assistants and AI summaries return one composed answer and may name only a few sources, or none. That changes what your content needs to do: Traditional SEO AEO Goal Rank a page in a results list Be quoted or cited inside an answer ...
Read more