Replaces the source content of a specific cell
AI agents use notebook_edit_cell 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.
This tool modifies existing cell content reversibly (can be edited again or undone), making it a Write operation rather than Execute or Destructive. However, severity is high because modifying notebook cells could alter computational logic, inject malicious code, or corrupt analysis workflows if misused by an AI agent. The cell content itself is not deleted (which would be Destructive), but changed.
From the tool's definition Tool name 'notebook_edit_cell' and description 'Replaces the source content of a specific cell' indicate modification of notebook cell code/content.
Documented attack patterns abuse exactly the kind of access notebook_edit_cell gives an agent:
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:
{
"version": "1",
"default": "deny",
"tools": {
"notebook_edit_cell": {
"limits": [
{
"counter": "notebook_edit_cell_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} notebook_edit_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.
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Replaces the source content of a specific cell. 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.
Register the Claude Code Notebook MCP server in PolicyLayer and add a rule for notebook_edit_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 Claude Code Notebook MCP. Nothing to install.
notebook_edit_cell is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the notebook_edit_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.
Set action: deny in the PolicyLayer policy for notebook_edit_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.
notebook_edit_cell 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.
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.
Free to start. No card required.
29 Claude Code Notebook MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.