# list_families

Use when the agent wants to enumerate the probe families codeitall has covered — typically before constructing a compare_implementations(task=…) call, or to recover from a typo flagged by compare_implementations's near-miss diagnostics. Returns the canonical family list with one-line descriptions, per-family counts, and the registered sub-family tags (Phase 1.12 W5; pass any as subfamily to compare_implementations): { families: [{ name, description, n_implementations, n_observations, sub_families }, …] }. The family names returned here are exactly the strings accepted by compare_implementations. No required parameters.

Agent View of the PolicyLayer registry record for `list_families`. HTML page: https://policylayer.com/tools/dev-codeitall-codeitall/list-families

## Facts

- Tool: `list_families`
- Server: Codeitall (`https://api.codeitall.dev/mcp`) — https://policylayer.com/tools/dev-codeitall-codeitall.md
- Homepage: https://github.com/codeitalldev/codeitall
- Risk category: Read (Low risk)
- Registry record: grade B, identity unverified
- Server rate-limited: no
- Parameters: 1
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `language` | string | no |  |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "list_families",
    "arguments": {}
  }
}
```

## Why list_families is rated Low

This tool performs a pure query/retrieval operation to list available probe families and their metadata. It has no capability to modify data, execute operations, delete resources, or affect financial systems. The primary use case stated is enumerating families "before constructing" calls to other tools, making it clearly informational/preparatory in nature.

From the tool's own definition: "Tool description states it 'enumerate[s] the probe families' and 'Returns the canonical family list with one-line descriptions, per-family counts, and the registered sub-family tags.' The action is retrieving and listing metadata about available families with…"

## Use case

AI agents call list_families to retrieve information from Codeitall without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Codeitall:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "list_families": {}
  }
}
```

## Other tools on Codeitall (7)

- `answer_api_question` — Read — https://policylayer.com/tools/dev-codeitall-codeitall/answer-api-question.md
- `behavior_lookup` — Read — https://policylayer.com/tools/dev-codeitall-codeitall/behavior-lookup.md
- `compare_implementations` — Read — https://policylayer.com/tools/dev-codeitall-codeitall/compare-implementations.md
- `find_modern_equivalent` — Read — https://policylayer.com/tools/dev-codeitall-codeitall/find-modern-equivalent.md
- `package_trust` — Read — https://policylayer.com/tools/dev-codeitall-codeitall/package-trust.md
- `pattern_consensus` — Read — https://policylayer.com/tools/dev-codeitall-codeitall/pattern-consensus.md
- `signature_search` — Read — https://policylayer.com/tools/dev-codeitall-codeitall/signature-search.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=dev-codeitall-codeitall · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/dev-codeitall-codeitall