# read_file_metadata

Read metadata directly from the ebook file itself (EPUB, MOBI, etc.).

Agent View of the PolicyLayer registry record for `read_file_metadata`. HTML page: https://policylayer.com/tools/2b3pro-calibre-mcp/read-file-metadata

## Facts

- Tool: `read_file_metadata`
- Server: Calibre (`2b3pro/calibre-mcp`) — https://policylayer.com/tools/2b3pro-calibre-mcp.md
- Homepage: https://github.com/2b3pro/calibre-mcp
- Risk category: Read (Low risk)
- Registry record: grade B, 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": "read_file_metadata",
    "arguments": {}
  }
}
```

## Why read_file_metadata is rated Low

This tool retrieves metadata from ebook files without altering them. It is a pure read operation with no capability to modify, execute code, delete data, or incur financial consequences. The blast radius of misuse is minimal—an attacker could learn bibliographic information about stored ebooks but cannot modify or destroy them.

From the tool's own definition: "Tool name is 'read_file_metadata' and description states 'Read metadata directly from the ebook file itself'. The verb 'read' and 'read metadata' clearly indicate data retrieval with no modification or side effects."

## Use case

AI agents call read_file_metadata to retrieve information from Calibre 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 Calibre:

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

## Other tools on Calibre (9)

- `deep_search_book` — Read — https://policylayer.com/tools/2b3pro-calibre-mcp/deep-search-book.md
- `fetch_online_metadata` — Read — https://policylayer.com/tools/2b3pro-calibre-mcp/fetch-online-metadata.md
- `get_toc` — Read — https://policylayer.com/tools/2b3pro-calibre-mcp/get-toc.md
- `read_content` — Read — https://policylayer.com/tools/2b3pro-calibre-mcp/read-content.md
- `search_library` — Read — https://policylayer.com/tools/2b3pro-calibre-mcp/search-library.md
- `convert_ebook` — Write — https://policylayer.com/tools/2b3pro-calibre-mcp/convert-ebook.md
- `polish_book` — Write — https://policylayer.com/tools/2b3pro-calibre-mcp/polish-book.md
- `update_metadata` — Write — https://policylayer.com/tools/2b3pro-calibre-mcp/update-metadata.md
- `write_file_metadata` — Write — https://policylayer.com/tools/2b3pro-calibre-mcp/write-file-metadata.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=2b3pro-calibre-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/2b3pro-calibre-mcp