cell_move · Jupyter MCP: Risk & Policy

WHAT IT DOES

What cell_move does on JupyterMCP

AI agents use cell_move 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 cell_move needs a policy

cell_move creates or modifies notebook state reversibly—reordering cells can be undone by moving them back. It does not execute code (cell_execute is separate), delete data (cell_delete is separate), or cause irreversible harm.

From the tool's definition Tool description states 'Move a cell to a new position in the notebook.' This modifies the notebook structure by reordering cells, which is a reversible change.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

cell_move Rate-limited

cell_move 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": {
    "cell_move": {
      "limits": [
        {
          "counter": "cell_move_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 cell_move

What does the cell_move tool do? +

Move a cell to a new position in the notebook. 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 cell_move? +

Register the Jupyter MCP server in PolicyLayer and add a rule for cell_move: 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 cell_move? +

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

Can I rate-limit cell_move? +

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

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

cell_move 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.