open_note_preview · Anki MCP: Risk & Policy

WHAT IT DOES

What open_note_preview does on Anki

AI agents invoke open_note_preview to trigger actions in Anki. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why open_note_preview needs a policy

This tool triggers an external operation (opening Anki Browser preview), which is an Execute-category action. It doesn't read/return data to the caller, write/modify data, or perform destructive/financial operations. The blast radius is low since it only opens a UI preview window for human review.

From the tool's definition 'Open the existing note in Anki Browser preview' — triggers an external UI action in the Anki application

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

open_note_preview Rate-limited

open_note_preview stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "open_note_preview": {
      "limits": [
        {
          "counter": "open_note_preview_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Anki, so you can run agents against it safely.

FAQ

Questions about open_note_preview

What does the open_note_preview tool do? +

Open the existing note in Anki Browser preview for human review. It is categorised as a Execute tool in the Anki MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on open_note_preview? +

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

What risk level is open_note_preview? +

open_note_preview is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit open_note_preview? +

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

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

open_note_preview is provided by the Anki MCP server (yama662607/anki-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.