batch_modify_emails · Gmail MCP: Risk & Policy

WHAT IT DOES

What batch_modify_emails does on Gmail

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

WHY IT NEEDS A POLICY

Why batch_modify_emails needs a policy

Modifying labels is a write operation that changes email state reversibly; users can re-apply or remove labels. While high-severity due to potential for large-scale unintended modifications across multiple emails (batch operation) and the sensitive nature of Gmail data, it does not rise to Destructive (labels can be changed back) or Execute (no code/command execution).

From the tool's definition Tool description states it 'Modifies labels for multiple emails in batches' — a reversible modification operation. The context shows this is a Gmail management tool operating on email metadata (labels), not destructive deletion.

Risk signalsBulk/mass operation — affects multiple targets

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

batch_modify_emails Rate-limited

batch_modify_emails 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": {
    "batch_modify_emails": {
      "limits": [
        {
          "counter": "batch_modify_emails_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, so you can run agents against it safely.

FAQ

Questions about batch_modify_emails

What does the batch_modify_emails tool do? +

Modifies labels for multiple emails in batches. It is categorised as a Write tool in the Gmail MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on batch_modify_emails? +

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

What risk level is batch_modify_emails? +

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

Can I rate-limit batch_modify_emails? +

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

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

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