# head

Makes an HTTP HEAD request via curl and returns structured response headers (no body). Use to check resource existence, content type, or cache headers.

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

## Facts

- Tool: `head`
- Server: Git (`Dave-London/Pare`) — https://policylayer.com/tools/io-github-dave-london-git.md
- Homepage: https://github.com/Dave-London/pare
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

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

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

## Why head is rated Low

HTTP HEAD requests are inherently read-only operations used for checking resource metadata (existence, content type, cache headers) without side effects. No data is created, modified, deleted, or executed. This is a safe information retrieval operation.

From the tool's own definition: "Tool description states 'Makes an HTTP HEAD request via curl and returns structured response headers (no body).' HEAD requests are non-destructive read operations that retrieve only headers without modifying any data."

## Use case

AI agents call head to retrieve information from Git 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 Git:

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

## Other tools on Git (201)

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