update_vacation · Gmail MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_vacation does on Gmail MCP Server

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

WHY IT NEEDS A POLICY

Why update_vacation needs a policy

This tool creates or modifies account settings reversibly. A user can change vacation responder settings back to previous states, or disable the responder entirely. While potentially disruptive if misconfigured (e.g., auto-responding to all mail unexpectedly), the effect is reversible and represents a configuration write rather than destructive action, code execution, or financial impact.

From the tool's definition Tool name is "update_vacation" and description states it "Update[s] vacation responder settings". This modifies email account configuration settings (vacation responder) but does not delete data or execute arbitrary code.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_vacation Rate-limited

update_vacation 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": {
    "update_vacation": {
      "limits": [
        {
          "counter": "update_vacation_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 Gmail MCP Server, so you can run agents against it safely.

FAQ

Questions about update_vacation

What does the update_vacation tool do? +

Update vacation responder settings. It is categorised as a Write tool in the Gmail MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_vacation? +

Register the Gmail MCP Server MCP server in PolicyLayer and add a rule for update_vacation: 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 Gmail MCP Server. Nothing to install.

What risk level is update_vacation? +

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

Can I rate-limit update_vacation? +

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

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

update_vacation is provided by the Gmail MCP Server MCP server (nk900600/gmail-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.