> ## Documentation Index
> Fetch the complete documentation index at: https://platform.atlan.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Understand the tool catalog

> Distinguish Registry tools, extension tools, and account-specific downstream tools.

# Understand the tool catalog

Atlan MCP returns one namespaced catalog assembled from several providers. The
five Registry pages in this tab cover the stable built-in surface. They do not
enumerate every tool a connected account can expose.

## Where tools come from

| Provider                      | Current source state                                                                                                                       | How to verify it                                                                                   |
| ----------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------- |
| Registry                      | Five built-in tools for session setup and artifact reads.                                                                                  | Compare the Registry pages with authenticated `tools/list`.                                        |
| First-party extensions        | Current `main` declares none. Earlier deployments can expose the compatibility tools documented under **Skill tools** and **Agent tools**. | Inspect the extension declarations and authenticated `tools/list` for the Gateway version you run. |
| Registered downstream servers | Dynamic and account-specific. Each server can expose its own tools, including skill-oriented tools.                                        | Read the connected account's authenticated `tools/list`.                                           |

Gateway advertises names as `<server-slug>__<tool-name>`. Registry owns the
reserved `registry` slug. Downstream slugs come from server names and can gain a
numeric suffix when names collide, so copy the advertised name rather than
constructing it yourself.

## Skill tools and Skill metadata

Earlier Gateway versions declared `create_skill`, `get_skill`, and
`skill_traces` from the Skill extension. They are documented in this tab for
deployments that still advertise them. The Agent extension's `agent_traces`
tool is documented on the same basis. All four are retired in current `main`.

Use Registry's generic artifact tools to find and inspect Skills. Publish a
Skill through the CLI or HTTP API, and use the HTTP trace endpoints for Skill
trace reads.

A Skill's `allowed-tools` frontmatter is descriptive metadata. It records tool
dependencies but does not register or expose those tools through Gateway. A
skill-oriented tool can still appear when a registered downstream server
advertises it.

## Check the live catalog

After OAuth succeeds, inspect the MCP protocol's authenticated `tools/list`
result before constructing a call. For every tool you plan to use, confirm:

1. The exact namespaced name.
2. The current description and `inputSchema`.
3. Whether Gateway added `rationale` or `session_id`.
4. Which server namespace owns the tool.

`GET /mcp/v1/tools` is the searchable Registry projection of discovered tool
records. It is useful for inventory and reporting, but it can lag a downstream
server's live catalog. Use protocol `tools/list` to decide what is callable.