add_book · Personal Library MCP Server MCP: Risk & Policy

WHAT IT DOES

What add_book does on Personal Library MCP Server

AI agents use add_book to create or update resources in Personal Library MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Personal Library MCP Server environment.

WHY IT NEEDS A POLICY

Why add_book needs a policy

Adding a book creates a new record in the SQLite database but is fully reversible—the book entry can be deleted or corrected. This is a straightforward data creation operation with no side effects beyond the database modification itself. Severity is low because misuse would only add unwanted entries to a personal reading list, causing no financial, security, or system damage.

From the tool's definition Tool description states it 'Adds a new book to the library.' The sibling tools include delete_book (destructive), list_books (read), search_books (read), and update_book_status (write), confirming this is a write operation that creates new data reversibly.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_book Rate-limited

add_book stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "add_book": {
      "limits": [
        {
          "counter": "add_book_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Personal Library MCP Server, so you can run agents against it safely.

FAQ

Questions about add_book

What does the add_book tool do? +

Adds a new book to the library. It is categorised as a Write tool in the Personal Library MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_book? +

Register the Personal Library MCP Server MCP server in PolicyLayer and add a rule for add_book: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Personal Library MCP Server. Nothing to install.

What risk level is add_book? +

add_book is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit add_book? +

Yes. Add a rate_limit block to the add_book rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block add_book completely? +

Set action: deny in the PolicyLayer policy for add_book. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides add_book? +

add_book is provided by the Personal Library MCP Server MCP server (srgsanky/mcp-demo). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.