# 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-pare-test/head

## Facts

- Tool: `head`
- Server: Test (`Dave-London/Pare`) — https://policylayer.com/tools/io-github-dave-london-pare-test.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 non-destructive read operations used for checking resource metadata such as existence, content type, and cache headers. They have no side effects, cannot modify data, and pose minimal security risk even if misused by an AI agent. The worst-case scenario is retrieving unwanted metadata or probing for information about a resource, which constitutes a Read-category risk.

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

## Use case

AI agents call head to retrieve information from Test 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 Test:

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

## Other tools on Test (201)

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