# polish_book

Perform maintenance on a book (EPUB/AZW3) to

Agent View of the PolicyLayer registry record for `polish_book`. HTML page: https://policylayer.com/tools/2b3pro-calibre-mcp/polish-book

## Facts

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

## Why polish_book is rated Medium

The tool performs maintenance on ebook files (EPUB/AZW3), which implies modifying existing files. 'Maintenance' operations typically restructure, clean up, or update file contents in-place. This is a Write operation as it modifies existing data, though since the description is cut off we cannot confirm if it has destructive or irreversible aspects. Confidence is reduced due to the truncated description.

From the tool's own definition: "'Perform maintenance on a book (EPUB/AZW3)' - description is truncated/uninformative beyond indicating it modifies book files"

## Use case

AI agents use polish_book to create or update resources in Calibre, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Calibre environment.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Calibre:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "polish_book": {
      "limits": [
        {
          "counter": "polish_book_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## 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
- `read_file_metadata` — Read — https://policylayer.com/tools/2b3pro-calibre-mcp/read-file-metadata.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
- `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