gmail_add_label_to_messages · Gmail MCP Server MCP

WHAT IT DOES

What gmail_add_label_to_messages does on Gmail MCP Server

AI agents use gmail_add_label_to_messages 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 gmail_add_label_to_messages needs a policy

Adding labels to messages is a reversible modification operation that changes email organization state without deleting data or executing external code. It qualifies as Write rather than Read (which would be retrieval-only) or Execute (which would be for running arbitrary commands).

From the tool's definition Tool performs 'Add a label' action which modifies message metadata. Description explicitly states it modifies messages by adding labels, and accepts message IDs or search queries as arguments.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

gmail_add_label_to_messages Rate-limited

gmail_add_label_to_messages 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_add_label_to_messages": {
      "limits": [
        {
          "counter": "gmail_add_label_to_messages_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 Gmail MCP Server, so you can run agents against it safely.

FAQ

Questions about gmail_add_label_to_messages

What does the gmail_add_label_to_messages tool do? +

Add a label to one or more messages. Can specify messages by IDs or by search query. 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 gmail_add_label_to_messages? +

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

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

Can I rate-limit gmail_add_label_to_messages? +

Yes. Add a rate_limit block to the gmail_add_label_to_messages 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_add_label_to_messages completely? +

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

gmail_add_label_to_messages is provided by the Gmail MCP Server MCP server (murphy360/mcp_gmail). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.