modify_gmail_message · Google Connections MCP: Risk & Policy

WHAT IT DOES

What modify_gmail_message does on Google Connections

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

WHY IT NEEDS A POLICY

Why modify_gmail_message needs a policy

This tool modifies Gmail message labels (tags/folders), which is a reversible Write operation. It does not delete messages (Destructive), execute code (Execute), process payments (Financial), or merely read data (Read).

From the tool's definition Tool name is 'modify_gmail_message' and description states it 'Modify labels on a Gmail message.' Labels are metadata that can be added, removed, or changed, representing reversible modifications to message organization rather than permanent deletion or…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

modify_gmail_message Rate-limited

modify_gmail_message 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": {
    "modify_gmail_message": {
      "limits": [
        {
          "counter": "modify_gmail_message_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 Google Connections, so you can run agents against it safely.

FAQ

Questions about modify_gmail_message

What does the modify_gmail_message tool do? +

Modify labels on a Gmail message. It is categorised as a Write tool in the Google Connections MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on modify_gmail_message? +

Register the Google Connections MCP server in PolicyLayer and add a rule for modify_gmail_message: 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 Google Connections. Nothing to install.

What risk level is modify_gmail_message? +

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

Can I rate-limit modify_gmail_message? +

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

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

modify_gmail_message is provided by the Google Connections MCP server (michaelzrork/google-connections-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.