add_file_attachment · MCP Apple Reminders MCP: Risk & Policy

WHAT IT DOES

What add_file_attachment does on MCP Apple Reminders

AI agents use add_file_attachment 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 add_file_attachment needs a policy

File attachment is a write operation that modifies reminder objects but is reversible (attachments can be removed). The empty description lowers confidence slightly, but the name and server context clearly indicate modification of reminder data. Severity is medium due to potential for attaching unwanted files to reminders, affecting user experience, but the operation itself is not destructive or irreversible.

From the tool's definition Tool name 'add_file_attachment' combined with server description indicating 'create, update, delete, search, and organization of reminders'; the tool modifies reminders by attaching files, a reversible operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_file_attachment Rate-limited

add_file_attachment 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": {
    "add_file_attachment": {
      "limits": [
        {
          "counter": "add_file_attachment_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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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 add_file_attachment

What does the add_file_attachment tool do? +

add_file_attachment. 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 add_file_attachment? +

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

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

Can I rate-limit add_file_attachment? +

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

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

add_file_attachment 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.