create_custom_voice

THE RISK

High Risk

Why create_custom_voice needs a policy

This tool triggers an external operation (creating a custom voice resource) via Apple Shortcuts/macOS CLI. It goes beyond a simple write as it likely invokes system-level or AI voice synthesis processes. The description doesn't clarify reversibility, but creating a voice model is an Execute-level operation.

From the tool's definition Create a custom voice from a text description of desired voice characteristics

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

POLICY

How to control create_custom_voice

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 create_custom_voice:

policy.json

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

create_custom_voice 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.

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.

RATE-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 →

Execute tools on other servers

Android Forensics ADB MCP Server adb_shell_command EMBA-MCP run_emba_scan Frida Game Hacking MCP remove_breakpoint Procmon request_elevation

Go deeper

High-risk tools in Apple Shortcuts → Every high-risk tool this server exposes, in one view.
All high-risk MCP tools → Every high-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Agent sandbox → Bounding what an agent can execute and where the boundary should sit.
Least privilege for MCP → Granting agents the minimum tool surface the task needs.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about create_custom_voice

What does the create_custom_voice tool do? +

Create a custom voice from a text description of desired voice characteristics. It is categorised as a Execute tool in the Apple Shortcuts MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on create_custom_voice? +

Register the Apple Shortcuts MCP server in PolicyLayer and add a rule for create_custom_voice: 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 create_custom_voice? +

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

Can I rate-limit create_custom_voice? +

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

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

create_custom_voice 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 →