Medium Risk

notebook_edit_cell_output

Allows direct manipulation and setting of cell outputs

How to control notebook_edit_cell_output ↓

What notebook_edit_cell_output does on Claude Code Notebook MCP

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

Medium Risk

Why notebook_edit_cell_output needs a policy

This tool modifies cell outputs in a Jupyter notebook, which is reversible (outputs can be re-executed or overwritten). It does not irreversibly delete data (Destructive), execute code (Execute), move money (Financial), or merely query data (Read).

From the tool's definition Tool description states it 'Allows direct manipulation and setting of cell outputs' — modifying notebook outputs is a Write operation that creates or modifies data.

Documented attack patterns abuse exactly the kind of access notebook_edit_cell_output gives an agent:

How to control notebook_edit_cell_output

PolicyLayer is an MCP gateway — it sits between your AI agents and Claude Code Notebook MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for notebook_edit_cell_output:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "notebook_edit_cell_output": {
      "limits": [
        {
          "counter": "notebook_edit_cell_output_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

notebook_edit_cell_output 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.

  1. Create a free account and register Claude Code Notebook MCP — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
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Related tools and policies

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Questions about notebook_edit_cell_output

What does the notebook_edit_cell_output tool do? +

Allows direct manipulation and setting of cell outputs. It is categorised as a Write tool in the Claude Code Notebook MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on notebook_edit_cell_output? +

Register the Claude Code Notebook MCP server in PolicyLayer and add a rule for notebook_edit_cell_output: 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 Claude Code Notebook MCP. Nothing to install.

What risk level is notebook_edit_cell_output? +

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

Can I rate-limit notebook_edit_cell_output? +

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

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

notebook_edit_cell_output is provided by the Claude Code Notebook MCP server (mstampfer/claude-code-notebook-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Claude Code Notebook MCP tool call.

Start from Claude Code Notebook MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

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29 Claude Code Notebook MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

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