# extract_metadata

Extract page metadata including JSON-LD, Open Graph, Twitter cards, and standard meta tags.

Agent View of the PolicyLayer registry record for `extract_metadata`. HTML page: https://policylayer.com/tools/1600822305-js-reverse-mcp/extract-metadata

## Facts

- Tool: `extract_metadata`
- Server: Js Reverse (`1600822305/js-reverse-mcp`) — https://policylayer.com/tools/1600822305-js-reverse-mcp.md
- Homepage: https://github.com/1600822305/js-reverse-mcp
- 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": "extract_metadata",
    "arguments": {}
  }
}
```

## Why extract_metadata is rated Low

This tool performs passive data retrieval of metadata already present in the DOM. It has no side effects, cannot modify or delete data, and poses minimal risk even if misused by an AI agent—the data extracted is publicly visible in the page source. Classified as Read with low severity.

From the tool's own definition: "Tool description states it 'Extract[s] page metadata' from standard, publicly-exposed meta tags (JSON-LD, Open Graph, Twitter cards, meta tags). No modification, deletion, or execution of code is indicated."

## Use case

AI agents call extract_metadata to retrieve information from Js Reverse 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 Js Reverse:

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

## Other tools on Js Reverse (92)

- `clear_browser_cache` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/clear-browser-cache.md
- `clear_cookies` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/clear-cookies.md
- `clear_network_conditions` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/clear-network-conditions.md
- `delete_cookie` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/delete-cookie.md
- `delete_token` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/delete-token.md
- `remove_breakpoint` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/remove-breakpoint.md
- `remove_dom_breakpoint` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/remove-dom-breakpoint.md
- `remove_network_rule` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/remove-network-rule.md
- `remove_xhr_breakpoint` — Destructive — https://policylayer.com/tools/1600822305-js-reverse-mcp/remove-xhr-breakpoint.md
- `add_network_rule` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/add-network-rule.md
- `api_request` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/api-request.md
- `batch_replay` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/batch-replay.md
- `break_on_attribute_modified` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/break-on-attribute-modified.md
- `break_on_node_removed` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/break-on-node-removed.md
- `break_on_subtree_modified` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/break-on-subtree-modified.md
- `break_on_xhr` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/break-on-xhr.md
- `encode_protobuf` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/encode-protobuf.md
- `evaluate_on_callframe` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/evaluate-on-callframe.md
- `evaluate_script` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/evaluate-script.md
- `hook_crypto_functions` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/hook-crypto-functions.md
- `hook_function` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/hook-function.md
- `monitor_events` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/monitor-events.md
- `monitor_eventsource` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/monitor-eventsource.md
- `monitor_form_submit` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/monitor-form-submit.md
- `monitor_input_changes` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/monitor-input-changes.md
- `navigate_page` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/navigate-page.md
- `new_page` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/new-page.md
- `pause` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/pause.md
- `replay_request` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/replay-request.md
- `resume` — Execute — https://policylayer.com/tools/1600822305-js-reverse-mcp/resume.md
- …and 62 more: https://policylayer.com/tools/1600822305-js-reverse-mcp.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`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=1600822305-js-reverse-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/1600822305-js-reverse-mcp
