create_note · Joplin MCP: Risk & Policy

WHAT IT DOES

What create_note does on Joplin

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

WHY IT NEEDS A POLICY

Why create_note needs a policy

This tool creates new notes, which is a reversible write operation. It does not execute code, delete data, move money, or cause destructive side effects. The impact is limited to adding new content to the note-taking application. Severity is low because note creation has minimal blast radius—an AI agent creating unwanted notes can be easily remedied by deletion.

From the tool's definition Tool name 'create_note' and description 'Create a new note in Joplin' indicate data creation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_note Rate-limited

create_note 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": {
    "create_note": {
      "limits": [
        {
          "counter": "create_note_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 Joplin, so you can run agents against it safely.

FAQ

Questions about create_note

What does the create_note tool do? +

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

How do I enforce a policy on create_note? +

Register the Joplin MCP server in PolicyLayer and add a rule for create_note: 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 Joplin. Nothing to install.

What risk level is create_note? +

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

Can I rate-limit create_note? +

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

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

create_note is provided by the Joplin MCP server (joplin-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.