ipynb_str_replace_in_cell · Jupyter Editor MCP

WHAT IT DOES

What ipynb_str_replace_in_cell does on Jupyter Editor

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

WHY IT NEEDS A POLICY

Why ipynb_str_replace_in_cell needs a policy

The tool modifies notebook cell content via string replacement. This is a Write operation because it creates or modifies data reversibly—replaced strings can be reverted by replacing them back. The description is empty, lowering confidence slightly, but the name is clear and the context of a notebook editor with batch-processing capabilities indicates this tool modifies cell contents.

From the tool's definition Tool name 'ipynb_str_replace_in_cell' indicates string replacement within a notebook cell. Sibling tools include 'ipynb_append_cell', 'ipynb_delete_cell', and 'ipynb_clear_outputs', establishing this server's capability to modify notebook content.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

ipynb_str_replace_in_cell Rate-limited

ipynb_str_replace_in_cell 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": {
    "ipynb_str_replace_in_cell": {
      "limits": [
        {
          "counter": "ipynb_str_replace_in_cell_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 Jupyter Editor, so you can run agents against it safely.

FAQ

Questions about ipynb_str_replace_in_cell

What does the ipynb_str_replace_in_cell tool do? +

ipynb_str_replace_in_cell. It is categorised as a Write tool in the Jupyter Editor MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on ipynb_str_replace_in_cell? +

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

What risk level is ipynb_str_replace_in_cell? +

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

Can I rate-limit ipynb_str_replace_in_cell? +

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

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

ipynb_str_replace_in_cell is provided by the Jupyter Editor MCP server (jsamuel1/jupyter-editor-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.