obsidian_create_note · Obsidian MCP: Risk & Policy

WHAT IT DOES

What obsidian_create_note does on Obsidian

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

WHY IT NEEDS A POLICY

Why obsidian_create_note needs a policy

Creating a note is a reversible write operation that modifies the note collection by adding new data. It does not execute code, delete data irreversibly, or move money. While it has side effects, they can be undone (the note can be deleted), making it Write rather than Execute or Destructive.

From the tool's definition Tool name is 'obsidian_create_note' and description states it 'Creates a new note.' The server description confirms it allows LLMs to 'read/write notes.'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

obsidian_create_note Rate-limited

obsidian_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": {
    "obsidian_create_note": {
      "limits": [
        {
          "counter": "obsidian_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 Obsidian, so you can run agents against it safely.

FAQ

Questions about obsidian_create_note

What does the obsidian_create_note tool do? +

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

How do I enforce a policy on obsidian_create_note? +

Register the Obsidian MCP server in PolicyLayer and add a rule for obsidian_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 Obsidian. Nothing to install.

What risk level is obsidian_create_note? +

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

Can I rate-limit obsidian_create_note? +

Yes. Add a rate_limit block to the obsidian_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 obsidian_create_note completely? +

Set action: deny in the PolicyLayer policy for obsidian_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 obsidian_create_note? +

obsidian_create_note is provided by the Obsidian MCP server (yuchi-chang/obsidian-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.