schedule_readings · Gcal MCP: Risk & Policy

WHAT IT DOES

What schedule_readings does on Gcal

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

WHY IT NEEDS A POLICY

Why schedule_readings needs a policy

This tool creates calendar events for reading articles based on a reading queue. Creating calendar events is a reversible Write operation—events can be edited or deleted. The tool does not execute arbitrary code, delete data irreversibly, or move money.

From the tool's definition Tool description states it will "Batch-schedule all queued reading articles into available reading time slots on your calendar," which involves creating or modifying calendar entries.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

schedule_readings Rate-limited

schedule_readings 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": {
    "schedule_readings": {
      "limits": [
        {
          "counter": "schedule_readings_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 Gcal, so you can run agents against it safely.

FAQ

Questions about schedule_readings

What does the schedule_readings tool do? +

Batch-schedule all queued reading articles into available reading time slots on your calendar. Slots: ${readingSlotsDesc}. Checks for conflicts and skips occupied slots. It is categorised as a Write tool in the Gcal MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on schedule_readings? +

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

What risk level is schedule_readings? +

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

Can I rate-limit schedule_readings? +

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

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

schedule_readings is provided by the Gcal MCP server (kwikkid/gcalcli). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.