append_to_note · Obsidian Nexus MCP: Risk & Policy

WHAT IT DOES

What append_to_note does on Obsidian Nexus

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

WHY IT NEEDS A POLICY

Why append_to_note needs a policy

This tool modifies an existing markdown note by appending content to it. This is a Write operation as it creates or modifies data in a reversible manner (content can be removed). The blast radius is medium since it could pollute or corrupt notes with unwanted content, but it does not delete or overwrite existing data.

From the tool's definition 'Append content to an existing note' — adds data to an existing file reversibly

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

append_to_note Rate-limited

append_to_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": {
    "append_to_note": {
      "limits": [
        {
          "counter": "append_to_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 Nexus, so you can run agents against it safely.

FAQ

Questions about append_to_note

What does the append_to_note tool do? +

Append content to an existing note. It is categorised as a Write tool in the Obsidian Nexus MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on append_to_note? +

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

What risk level is append_to_note? +

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

Can I rate-limit append_to_note? +

Yes. Add a rate_limit block to the append_to_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 append_to_note completely? +

Set action: deny in the PolicyLayer policy for append_to_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 append_to_note? +

append_to_note is provided by the Obsidian Nexus MCP server (nkriman/obsidian-nexus). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.