set_list_appearance · MCP Apple Reminders MCP: Risk & Policy

WHAT IT DOES

What set_list_appearance does on MCP Apple Reminders

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

WHY IT NEEDS A POLICY

Why set_list_appearance needs a policy

The tool modifies list properties but does not create/delete data or trigger irreversible actions. Appearance changes are reversible updates. Severity is low because cosmetic modifications have minimal blast radius—they affect only visual presentation without compromising data integrity or enabling access to sensitive information.

From the tool's definition Tool name 'set_list_appearance' suggests modifying visual/display properties of a reminders list. Server description indicates the MCP exposes 'create, read, update, delete, search, and organization of reminders and lists.' Setting appearance (colors, icons,…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_list_appearance Rate-limited

set_list_appearance 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": {
    "set_list_appearance": {
      "limits": [
        {
          "counter": "set_list_appearance_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 MCP Apple Reminders, so you can run agents against it safely.

FAQ

Questions about set_list_appearance

What does the set_list_appearance tool do? +

set_list_appearance. It is categorised as a Write tool in the MCP Apple Reminders MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_list_appearance? +

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

What risk level is set_list_appearance? +

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

Can I rate-limit set_list_appearance? +

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

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

set_list_appearance is provided by the MCP Apple Reminders MCP server (rex/mcp-apple-reminders). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.