add_alarm · MCP Reminder MCP: Risk & Policy

WHAT IT DOES

What add_alarm does on MCP Reminder

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

WHY IT NEEDS A POLICY

Why add_alarm needs a policy

This tool creates or adds a new alarm entry to persistent storage, which is a reversible write operation. Users can dismiss or delete alarms later. It has no financial impact, does not execute external code, and does not delete data irreversibly. The blast radius is low—the worst case is a spurious alarm being set, which can be easily dismissed by the user or AI agent.

From the tool's definition Tool name 'add_alarm' with description '添加闹钟' (Chinese: 'add alarm') indicates creation of a new alarm/reminder entry. Sibling tools like 'add_todo', 'complete_todo', 'dismiss_alarm' confirm this server manages reversible state changes to reminders and todos.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_alarm Rate-limited

add_alarm 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_alarm": {
      "limits": [
        {
          "counter": "add_alarm_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 Reminder, so you can run agents against it safely.

FAQ

Questions about add_alarm

What does the add_alarm tool do? +

添加闹钟. It is categorised as a Write tool in the MCP Reminder 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_alarm? +

Register the MCP Reminder MCP server in PolicyLayer and add a rule for add_alarm: 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 Reminder. Nothing to install.

What risk level is add_alarm? +

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

Can I rate-limit add_alarm? +

Yes. Add a rate_limit block to the add_alarm 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_alarm completely? +

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

add_alarm is provided by the MCP Reminder MCP server (sheacoding/mcp-reminder). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.