add_source · Notebooklm MCP: Risk & Policy

WHAT IT DOES

What add_source does on Notebooklm

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

WHY IT NEEDS A POLICY

Why add_source needs a policy

This tool adds or uploads content (sources) to a notebook, which is a reversible modification operation. It does not delete data (Destructive), execute arbitrary code (Execute), or move money (Financial). The 'medium' severity reflects that unauthorized source ingestion could pollute a notebook with incorrect information, but the impact is limited to that specific notebook and the action is reversible via deletion.

From the tool's definition Tool description states 'Ingest a source into a NotebookLM notebook', which is a create/add operation that modifies notebook contents. The verb 'ingest' combined with 'into' indicates data creation or addition to an existing resource.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_source Rate-limited

add_source 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_source": {
      "limits": [
        {
          "counter": "add_source_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, so you can run agents against it safely.

FAQ

Questions about add_source

What does the add_source tool do? +

Ingest a source into a NotebookLM notebook. Supports two source types. It is categorised as a Write tool in the Notebooklm 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_source? +

Register the Notebooklm MCP server in PolicyLayer and add a rule for add_source: 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. Nothing to install.

What risk level is add_source? +

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

Can I rate-limit add_source? +

Yes. Add a rate_limit block to the add_source 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_source completely? +

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

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