gmail_bulk_modify · Google MCP: Risk & Policy

WHAT IT DOES

What gmail_bulk_modify does on Google

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

WHY IT NEEDS A POLICY

Why gmail_bulk_modify needs a policy

'Bulk_modify' performs reversible changes to potentially large volumes of Gmail messages. This is Write-category (modification without deletion). Severity is high because bulk operations on email could affect many messages at once, causing unintended side effects if an AI agent misuses the batch parameters.

From the tool's definition Tool name 'gmail_bulk_modify' indicates bulk modification of Gmail data. While description is empty, the pattern of sibling tools on this server (calendar_create_event, calendar_delete_calendar, etc.) and the 'bulk_modify' naming convention strongly suggest…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

gmail_bulk_modify Rate-limited

gmail_bulk_modify 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": {
    "gmail_bulk_modify": {
      "limits": [
        {
          "counter": "gmail_bulk_modify_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Google, so you can run agents against it safely.

FAQ

Questions about gmail_bulk_modify

What does the gmail_bulk_modify tool do? +

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

How do I enforce a policy on gmail_bulk_modify? +

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

What risk level is gmail_bulk_modify? +

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

Can I rate-limit gmail_bulk_modify? +

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

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

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