# fmt

Checks or fixes Rust formatting and returns structured output.

Agent View of the PolicyLayer registry record for `fmt`. HTML page: https://policylayer.com/tools/io-github-dave-london-github/fmt

## Facts

- Tool: `fmt`
- Server: Github (`@paretools/github`) — https://policylayer.com/tools/io-github-dave-london-github.md
- Install: `npx -y @paretools/github`
- Homepage: https://github.com/Dave-London/Pare
- Risk category: Execute (High risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

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

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

## Why fmt is rated High

The tool both executes an external process (rustfmt) and can modify source files when in fix mode. Since it may overwrite code files, it crosses into Write territory, but because it triggers an external command whose effect depends on mode arguments, Execute is the most accurate primary category.

From the tool's own definition: "'Checks or fixes Rust formatting' — the 'fixes' action modifies source files in place; 'runs' an external formatter tool (rustfmt)"

## Use case

AI agents invoke fmt to trigger actions in Github. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

## Recommended policy (PolicyLayer)

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

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "fmt": {
      "limits": [
        {
          "counter": "fmt_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Github (201)

- `branch` — Destructive — https://policylayer.com/tools/io-github-dave-london-github/branch.md
- `clean` — Destructive — https://policylayer.com/tools/io-github-dave-london-github/clean.md
- `remove` — Destructive — https://policylayer.com/tools/io-github-dave-london-github/remove.md
- `reset` — Destructive — https://policylayer.com/tools/io-github-dave-london-github/reset.md
- `secret-delete` — Destructive — https://policylayer.com/tools/io-github-dave-london-github/secret-delete.md
- `stash` — Destructive — https://policylayer.com/tools/io-github-dave-london-github/stash.md
- `tag` — Destructive — https://policylayer.com/tools/io-github-dave-london-github/tag.md
- `variable-delete` — Destructive — https://policylayer.com/tools/io-github-dave-london-github/variable-delete.md
- `workspace` — Destructive — https://policylayer.com/tools/io-github-dave-london-github/workspace.md
- `worktree` — Destructive — https://policylayer.com/tools/io-github-dave-london-github/worktree.md
- `add` — Execute — https://policylayer.com/tools/io-github-dave-london-github/add.md
- `add-package` — Execute — https://policylayer.com/tools/io-github-dave-london-github/add-package.md
- `ansible-galaxy` — Execute — https://policylayer.com/tools/io-github-dave-london-github/ansible-galaxy.md
- `ansible-playbook` — Execute — https://policylayer.com/tools/io-github-dave-london-github/ansible-playbook.md
- `api` — Execute — https://policylayer.com/tools/io-github-dave-london-github/api.md
- `apply` — Execute — https://policylayer.com/tools/io-github-dave-london-github/apply.md
- `audit` — Execute — https://policylayer.com/tools/io-github-dave-london-github/audit.md
- `bazel` — Execute — https://policylayer.com/tools/io-github-dave-london-github/bazel.md
- `biome-check` — Execute — https://policylayer.com/tools/io-github-dave-london-github/biome-check.md
- `bisect` — Execute — https://policylayer.com/tools/io-github-dave-london-github/bisect.md
- `black` — Execute — https://policylayer.com/tools/io-github-dave-london-github/black.md
- `build` — Execute — https://policylayer.com/tools/io-github-dave-london-github/build.md
- `bundle-exec` — Execute — https://policylayer.com/tools/io-github-dave-london-github/bundle-exec.md
- `bundle-install` — Execute — https://policylayer.com/tools/io-github-dave-london-github/bundle-install.md
- `check` — Execute — https://policylayer.com/tools/io-github-dave-london-github/check.md
- `cherry-pick` — Execute — https://policylayer.com/tools/io-github-dave-london-github/cherry-pick.md
- `clippy` — Execute — https://policylayer.com/tools/io-github-dave-london-github/clippy.md
- `cmake` — Execute — https://policylayer.com/tools/io-github-dave-london-github/cmake.md
- `compose-build` — Execute — https://policylayer.com/tools/io-github-dave-london-github/compose-build.md
- `compose-down` — Execute — https://policylayer.com/tools/io-github-dave-london-github/compose-down.md
- …and 171 more: https://policylayer.com/tools/io-github-dave-london-github.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=io-github-dave-london-github · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-dave-london-github