gmail_modify_labels · Personal Gmail MCP: Risk & Policy

WHAT IT DOES

What gmail_modify_labels does on Personal Gmail

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

WHY IT NEEDS A POLICY

Why gmail_modify_labels needs a policy

This tool modifies email properties (labels) without deleting or destroying data. The operations are reversible—labels can be re-added or removed. While archiving removes from inbox view, it does not delete the message. This is a Write-category operation with medium severity due to potential for unintended bulk label changes that could hide or reorganize important messages, but no data loss or financial impact.

From the tool's definition Tool description states 'Add or remove labels on a message' which are reversible modifications to email metadata. Removing INBOX archives (reversible), adding STARRED stars it (reversible).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

gmail_modify_labels Rate-limited

gmail_modify_labels 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_modify_labels": {
      "limits": [
        {
          "counter": "gmail_modify_labels_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

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

FAQ

Questions about gmail_modify_labels

What does the gmail_modify_labels tool do? +

Add or remove labels on a message. Removing INBOX archives the message; adding STARRED stars it. Use gmail_list_labels for ids. It is categorised as a Write tool in the Personal 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 gmail_modify_labels? +

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

What risk level is gmail_modify_labels? +

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

Can I rate-limit gmail_modify_labels? +

Yes. Add a rate_limit block to the gmail_modify_labels 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_modify_labels completely? +

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

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