AI agent skills: today and what comes next

A two-person accounting firm takes on a new client who has kept records the same way for fifteen years. The handover includes a folder of Outlook messages saved one by one as .msg files. There is also an old mailbox export in .mbox format, plus a shoebox of receipts that someone has photographed as JPG files. Their agent can sort all of it, once it has the right skills.

The AI agent skills we publish

A skill is a packaged set of instructions, often with small scripts, that an agent reads when a job calls for it. Anthropic's guide to agent skills describes each one as a folder with a SKILL.md file at the top.

We publish 30 skills (September 2026). Most open files that modern tools struggle with and turn them into CSV, JSON or text:

• old Excel and Word files (.xls, .doc)
• saved email (.msg, .eml, .mbox)
• calendar exports and contact cards
• map and GPS files, such as KML, GPX and shapefiles
• data files, such as Parquet, Avro and SQLite
• OpenDocument files, the format LibreOffice uses (.odt, .ods, .odp)
• e-books and notebooks (.epub, .ipynb)
• scanned images, read with OCR (text recognition)

Each skill starts with a SKILL.md file you can read before you use it. The legacy Excel skill is a good one to open first. Twenty-nine of the 30 also have a hosted twin on our servers, which an agent can use with nothing to install.

Three ways into the index

The index is the larger part of what we offer. You can reach it three ways.

Agents connect through our MCP server. MCP, the Model Context Protocol, is an open standard that Anthropic introduced in 2024 for connecting AI assistants to tools and data. The server is also listed in the official MCP Registry as ai.stealthstack/discovery. It has three search tools, and none of them can change anything:

• search_resources returns the best matches for a request written in plain English.
• list_resources browses the index with filters, such as type or website.
• get_resource returns the full record for one listing, including how to connect.

In Claude Code, adding the server takes one line:

claude mcp add --transport http stealthstack https://stealthstack.ai/mcp

The Claude app and team plans take a few clicks instead, and our docs walk through each one. The tools section of the docs lists every option.

Software that doesn't use MCP can call our web API, which answers the same searches in JSON. People can use the search page in any browser. Whichever way you come in, each result carries the same record, including the website that published the tool and how your agent can reach it.

What agents can find

Our own skills are a small slice of the index. The rest comes from other makers who publish ARD files, which are lists of agent tools that businesses post on their own websites. ARD is an open specification, announced by Google and partners in June 2026. It's still young: version 0.91 is marked as a proposal that is still changing. Our ARD explainer covers the format. As of September 2026, we count more than 3,500 resources from 240 websites, including:

• more than 2,000 skills, which you can browse on their own
• more than 300 MCP servers
• about 280 web APIs
• close to 60 agents that other agents can talk to

Each search result is marked with its type, so you can tell a skill from an MCP server at a glance.

Most of these are developer tools. The business share is smaller but real. When we checked on September 28, 2026, a search for "create an invoice" returned an invoicing and accounting server published on its maker's own website as the first result. A search for "book an appointment" did worse: the top two matches were our own e-book reader and a service that lays out printed books. Gaps like that are why we build some tools ourselves, and what StealthStack is explains the ones we found first.

A quick run-through

Here is how the accounting firm's agent would handle that handover.

1. It searches our index for "read saved Outlook messages" and finds our .msg skill.
2. It loads the skill, or calls our hosted version, and turns each message into text with its sender, date and subject. The same skill lists details of any attachments, so the firm can see what each message carried.
3. It uses the .mbox skill on the old mailbox export in the same way.
4. It runs the OCR skill on the receipt photos, then hands the staff one tidy folder to review.

The firm still decides what matters and what to keep. The agent does the conversion.

What the skills won't do

These skills convert and extract. They don't judge what a file means, and they don't give tax, legal or financial advice. A badly damaged file may convert only in part, or not at all, so check the output before anything goes to a client. If you are unsure whether a skill fits your file, read its SKILL.md first. The description at the top says which formats it handles.

Where we are headed

We are sharing direction, not dates. Three things are on our list:

• Business categories. Today you find tools by describing the job. We want you to also browse by business need, such as finance, sales or operations.
• Federation. The ARD spec lets one registry refer a search to another. We are exploring searching across other registries, so one request reaches further.
• Business between agents. We want secure ways for your business's agents to work and trade with other companies' agents, including paid access to tools.

Next steps

1. Open the legacy Excel skill to see what a skill looks like inside.
2. Connect your assistant using our setup guide.
3. Browse the skills in our index for a file type that slows your team down.
4. Read why agents matter to small firms for the bigger picture.

Frequently asked questions

Do I need to be a developer to use these skills?

No. You need an AI assistant that supports skills or MCP, and a one-time setup. After that, you ask in ordinary words, like "convert this file to CSV."

What if there is no skill for my file type?

Search the whole index, including other makers' tools, because someone else may publish one. If nothing turns up, the job may still need a person or a developer for now.

Are StealthStack's skills free?

Yes. Our search tools and our own skills are free to use today, and you don't need an account.

Does a skill send my files to StealthStack?

Only if your agent calls our hosted version, which runs on our servers. When your agent loads the skill itself, the conversion runs wherever your agent runs, and our servers are not involved.