append · Obsidian Local MCP: Risk & Policy

WHAT IT DOES

What append does on Obsidian Local

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

WHY IT NEEDS A POLICY

Why append needs a policy

This tool adds content to an existing note without deleting or overwriting existing data. It is a reversible write operation (content can be removed), making it a Write category action. Misuse could add unwanted or malicious content to notes, warranting medium severity.

From the tool's definition Append content to the end of a note

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

append Rate-limited

append 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": {
      "limits": [
        {
          "counter": "append_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 Local, so you can run agents against it safely.

FAQ

Questions about append

What does the append tool do? +

Append content to the end of a note. It is categorised as a Write tool in the Obsidian Local 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? +

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

What risk level is append? +

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

Can I rate-limit append? +

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

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

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