set_parent · MCP Apple Reminders MCP: Risk & Policy

WHAT IT DOES

What set_parent does on MCP Apple Reminders

AI agents use set_parent 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_parent needs a policy

The tool modifies metadata/relationships of existing reminders (reassigning or detaching parent-child relationships) without deleting data or executing arbitrary code. This is a Write operation because it changes reminder organization reversibly. Severity is medium because misuse could reorganize a user's reminder structure, causing confusion or lost context, but changes are non-destructive and can be corrected.

From the tool's definition Tool name 'set_parent' and description 'Reassign or detach the parent of a reminder' indicates modification of reminder hierarchy/organization. This is a reversible structural change to existing reminders.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_parent Rate-limited

set_parent 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_parent": {
      "limits": [
        {
          "counter": "set_parent_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_parent

What does the set_parent tool do? +

Reassign or detach the parent of a reminder. Deferred — see description. 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_parent? +

Register the MCP Apple Reminders MCP server in PolicyLayer and add a rule for set_parent: 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_parent? +

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

Can I rate-limit set_parent? +

Yes. Add a rate_limit block to the set_parent 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_parent completely? +

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

set_parent 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.