draft_reply · Gmail MCP Server MCP: Risk & Policy

WHAT IT DOES

What draft_reply does on Gmail MCP Server

AI agents use draft_reply 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 draft_reply needs a policy

The server description explicitly mentions 'draft reply preparation without sending,' which classifies this as a Write operation — it creates a draft in Gmail but does not send the email, making it reversible. Confidence is moderate because the tool description is empty and classification relies on the tool name and server-level description.

From the tool's definition Tool name 'draft_reply' and server context 'draft reply preparation without sending' suggest creating a draft email (a reversible write action).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

draft_reply Rate-limited

draft_reply 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": {
    "draft_reply": {
      "limits": [
        {
          "counter": "draft_reply_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 draft_reply

What does the draft_reply tool do? +

draft_reply. 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 draft_reply? +

Register the Gmail MCP Server MCP server in PolicyLayer and add a rule for draft_reply: 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 draft_reply? +

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

Can I rate-limit draft_reply? +

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

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

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