source_add_url · NotebookLM MCP Server MCP: Risk & Policy

WHAT IT DOES

What source_add_url does on NotebookLM MCP Server

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

WHY IT NEEDS A POLICY

Why source_add_url needs a policy

This tool creates a new source entry in a notebook by adding a URL. This is a write operation that modifies notebook state reversibly—sources can be removed or replaced. The blast radius is medium because malicious URL injection could introduce misleading information into a research notebook, but the operation itself is not destructive and does not execute code or move funds.

From the tool's definition Tool name 'source_add_url' and description 'Add a URL...as a source to a notebook' indicate creation/modification of notebook sources.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

source_add_url Rate-limited

source_add_url 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": {
    "source_add_url": {
      "limits": [
        {
          "counter": "source_add_url_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 NotebookLM MCP Server, so you can run agents against it safely.

FAQ

Questions about source_add_url

What does the source_add_url tool do? +

Add a URL (webpage or YouTube) as a source to a notebook. It is categorised as a Write tool in the NotebookLM 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 source_add_url? +

Register the NotebookLM MCP Server MCP server in PolicyLayer and add a rule for source_add_url: 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 NotebookLM MCP Server. Nothing to install.

What risk level is source_add_url? +

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

Can I rate-limit source_add_url? +

Yes. Add a rate_limit block to the source_add_url 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 source_add_url completely? +

Set action: deny in the PolicyLayer policy for source_add_url. 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 source_add_url? +

source_add_url is provided by the NotebookLM MCP Server MCP server (pavelguzenfeld/notebooklm-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.