napkin_download_visual

THE RISK

Medium Risk

Why napkin_download_visual needs a policy

This tool writes a file to the local disk, which is a data-creation/modification action. It is reversible (the file can be deleted), so it falls under Write rather than Destructive. Severity is medium because an AI agent could write files to arbitrary locations on disk, potentially overwriting existing files.

From the tool's definition Download a generated Napkin visual file to disk

Documented attack patterns abuse exactly the kind of access napkin_download_visual gives an agent:

POLICY

How to control napkin_download_visual

PolicyLayer is an MCP gateway — it sits between your AI agents and Apple Shortcuts, and nothing reaches the server without passing your rules. This is the rule we recommend for napkin_download_visual:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "napkin_download_visual": {
      "limits": [
        {
          "counter": "napkin_download_visual_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

napkin_download_visual 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.

Create a free account and register Apple Shortcuts — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Apple Shortcuts tools

Destructive cancel_runway_task Cancel a pending/running task or delete a completed task. Saves credits if cancelled befor Destructive delete_custom_voice Delete a custom voice by ID. This is permanent and cannot be undone. Destructive delete_email Delete or move an email to trash. Destructive delete_event Delete a calendar event. Destructive delete_file Delete a file or folder from OneDrive. Destructive delete_library_item Delete a file or folder from a SharePoint document library. Destructive delete_list_item Delete an item from a SharePoint list. Destructive opus_cancel_scheduled_post Cancel a scheduled social post BEFORE its publishAt time.

All 423 Apple Shortcuts tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about napkin_download_visual

What does the napkin_download_visual tool do? +

Download a generated Napkin visual file to disk. It is categorised as a Write tool in the Apple Shortcuts MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on napkin_download_visual? +

Register the Apple Shortcuts MCP server in PolicyLayer and add a rule for napkin_download_visual: 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 Apple Shortcuts. Nothing to install.

What risk level is napkin_download_visual? +

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

Can I rate-limit napkin_download_visual? +

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

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

napkin_download_visual is provided by the Apple Shortcuts MCP server (@mindstone/mcp-server-apple-shortcuts). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Apple Shortcuts tool call.

Start from Apple Shortcuts, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →