updateDraft · Gmail MCP Server MCP: Risk & Policy

WHAT IT DOES

What updateDraft does on Gmail MCP Server

AI agents use updateDraft 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 updateDraft needs a policy

This tool creates or modifies data reversibly by updating an existing draft message. While drafts are user-controlled content, an AI agent could misuse this to alter draft content maliciously or introduce errors into user communications before sending. However, since the draft remains unsent and user-editable, the impact is bounded compared to sent emails or deletions.

From the tool's definition Tool name 'updateDraft' and description 'Update an existing Gmail draft message' indicate modification of existing data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

updateDraft Rate-limited

updateDraft 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": {
    "updateDraft": {
      "limits": [
        {
          "counter": "updatedraft_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 updateDraft

What does the updateDraft tool do? +

Update an existing Gmail draft message. 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 updateDraft? +

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

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

Can I rate-limit updateDraft? +

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

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

updateDraft is provided by the Gmail MCP Server MCP server (zacco16/gmail-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.