# MCP tools

> The three tools of the Context Atlas MCP server, with their inputs, example prompts and example answers.

All tools are read-only and answer with JSON as text. You rarely call them by name: ask your agent in plain language and it picks the tool. The example prompts below show what tends to trigger each one.

## search

Full-text search over tools (called topics) and their sources. It matches names, roles, regions, detection signals (files, dependencies, environment variables), source titles and URLs. Every word must match, as a prefix, so `post` finds Postgres.

| Input | Type | Description |
| --- | --- | --- |
| `query` | string, 1 to 200 characters | Words to search for, such as `database`, `vercel mcp` or `turbo.json` |
| `kind` | optional | Only return sources of this kind: `llms`, `full`, `docs`, `mcp`, `skill`, `rules` or `guide` |
| `limit` | optional, 1 to 50 | Maximum number of topics, default 10 |

Each result has the `topic` (without its sources), the matching `sources` and a `score` (lower is better). When the topic itself matched, `sources` holds all of its sources; when only some sources matched, just those.

**Example prompts**

- "Which Postgres hosts does contextatlas know?"
- "Find the MCP server for Vercel in contextatlas."
- "This repo has a turbo.json. What does contextatlas have for it?"

**Example call and answer** (shortened)

```json
{ "query": "neon", "limit": 1 }
```

```json
{
  "query": "neon",
  "results": [
    {
      "topic": {
        "id": "neon",
        "name": "Neon",
        "role": "Postgres database",
        "signals": [
          { "type": "dependency", "pattern": "@neondatabase/serverless" },
          { "type": "hint", "pattern": "DATABASE_URL pointing to *.neon.tech" }
        ],
        "region": { "id": "cloud", "name": "Cloud providers" }
      },
      "sources": [
        { "kind": "llms", "title": "Neon llms.txt", "url": "https://neon.com/llms.txt" },
        { "kind": "mcp", "title": "Neon MCP server", "url": "https://neon.com/docs/ai/neon-mcp-server" }
      ],
      "score": -4.32
    }
  ]
}
```

## get_topic

Everything the catalog has on one tool: its role, region, detection signals and all sources, plus `llmsTxt`, the URL of the topic's own small llms.txt file.

| Input | Type | Description |
| --- | --- | --- |
| `id` | string | Topic id as returned by `search` or `list_topics`, such as `vercel`, `nextjs` or `drizzle` |

**Example prompts**

- "Get the contextatlas topic for Drizzle and read its llms.txt."
- "What sources does contextatlas list for Cloudflare?"

**Example call and answer** (shortened)

```json
{ "id": "drizzle" }
```

```json
{
  "updatedAt": "2026-10-23",
  "topic": {
    "id": "drizzle",
    "name": "Drizzle ORM",
    "role": "ORM",
    "signals": [
      { "type": "file", "pattern": "drizzle.config.ts" },
      { "type": "dependency", "pattern": "drizzle-orm" }
    ],
    "sources": [
      { "kind": "llms", "title": "Drizzle llms.txt", "url": "https://orm.drizzle.team/llms.txt" }
    ],
    "region": { "id": "frameworks", "name": "Frameworks" },
    "llmsTxt": "https://contextatlas.dev/llms/drizzle.txt"
  }
}
```

An unknown id returns an error result, so the agent knows to search instead:

```json
{ "error": "Unknown topic \"nope\". Use search or list_topics to find ids." }
```

## list_topics

Every tool in the catalog with its id, name, role and region, without sources. Agents use it to find the candidates for each role, then call `get_topic` and read their llms.txt sources to choose. The catalog does not rank tools.

| Input | Type | Description |
| --- | --- | --- |
| `region` | optional string | Only this region: `cloud`, `frameworks`, `standards` or `clis` |

**Example prompts**

- "List the hosting options in contextatlas and pick one for a Next.js app."
- "What agent standards does contextatlas cover?"

**Example call and answer** (shortened)

```json
{ "region": "standards" }
```

```json
{
  "updatedAt": "2026-10-23",
  "topics": [
    {
      "id": "agent-skills",
      "name": "Agent Skills",
      "role": "Instructions",
      "region": "standards"
    },
    {
      "id": "agents-md",
      "name": "AGENTS.md",
      "role": "Instructions",
      "region": "standards"
    }
  ]
}
```

## Source kinds

The `kind` of a source tells the agent what to do with it:

| Kind | Meaning | What the agent should do |
| --- | --- | --- |
| `llms` | llms.txt, a machine-readable index of the docs | Fetch first |
| `rules` | Prompts and rule files to paste into an agent | Fetch first and follow |
| `guide` | How to work with agents on this platform | Read when relevant |
| `docs` | Full documentation or reference | Fetch the pages the task needs |
| `full` | All docs in one file, often several megabytes | Download and search it, never read it whole |
| `mcp` | An MCP server of the vendor | Offer to connect it, ask first |
| `skill` | Installable agent skills | Offer to install, ask first |