set_notebook_directory · Jupyter MCP: Risk & Policy

WHAT IT DOES

What set_notebook_directory does on JupyterMCP

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

WHY IT NEEDS A POLICY

Why set_notebook_directory needs a policy

This tool changes configuration state (working directory) reversibly without executing code, deleting data, or causing external side effects. It falls under Write (modifies data/state reversibly) rather than Execute because it sets a parameter rather than running computations.

From the tool's definition Tool description states it 'Set[s] the working directory for notebook operations', which modifies the operational state of the notebook environment.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_notebook_directory Rate-limited

set_notebook_directory 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": {
    "set_notebook_directory": {
      "limits": [
        {
          "counter": "set_notebook_directory_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 JupyterMCP, so you can run agents against it safely.

FAQ

Questions about set_notebook_directory

What does the set_notebook_directory tool do? +

Set the working directory for notebook operations. It is categorised as a Write tool in the JupyterMCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_notebook_directory? +

Register the Jupyter MCP server in PolicyLayer and add a rule for set_notebook_directory: 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 JupyterMCP. Nothing to install.

What risk level is set_notebook_directory? +

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

Can I rate-limit set_notebook_directory? +

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

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

set_notebook_directory is provided by the Jupyter MCP server (try3d/jupytermcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.