obsidian_write_note · Obsidian MCP Server MCP: Risk & Policy

WHAT IT DOES

What obsidian_write_note does on Obsidian MCP Server

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

WHY IT NEEDS A POLICY

Why obsidian_write_note needs a policy

The tool creates or modifies note content in an Obsidian vault, which is reversible and characteristic of Write category. While the description is empty (lowering confidence slightly), the explicit name and server context provide strong evidence.

From the tool's definition Tool name 'obsidian_write_note' directly indicates note creation/modification. Server description mentions 'creating atomic notes' and 'performing precise content editing operations' as core workflows.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

obsidian_write_note Rate-limited

obsidian_write_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_write_note": {
      "limits": [
        {
          "counter": "obsidian_write_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 MCP Server, so you can run agents against it safely.

FAQ

Questions about obsidian_write_note

What does the obsidian_write_note tool do? +

obsidian_write_note. It is categorised as a Write tool in the Obsidian MCP Server 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_write_note? +

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

What risk level is obsidian_write_note? +

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

Can I rate-limit obsidian_write_note? +

Yes. Add a rate_limit block to the obsidian_write_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_write_note completely? +

Set action: deny in the PolicyLayer policy for obsidian_write_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_write_note? +

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