# ruff-check

Runs ruff check and returns structured lint diagnostics (file, line, code, message).

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

## Facts

- Tool: `ruff-check`
- Server: Build (`Dave-London/Pare`) — https://policylayer.com/tools/io-github-dave-london-build.md
- 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": "ruff-check",
    "arguments": {}
  }
}
```

## Why ruff-check is rated High

The tool runs an external command (ruff check) against code files. While it is a read-only lint check with no data modification, it executes an external process whose behavior depends on arguments (file paths, config). This places it in Execute rather than Read. Blast radius is medium since it only reads/analyzes code but could be pointed at arbitrary files and consume resources.

From the tool's own definition: "'Runs ruff check' — actively executes the ruff linter as an external process"

## Use case

AI agents invoke ruff-check to trigger actions in Build. 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 Build:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "ruff-check": {
      "limits": [
        {
          "counter": "ruff-check_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Build (201)

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