gmail.addLabels · Gmail MCP Server MCP: Risk & Policy

WHAT IT DOES

What gmail.addLabels does on Gmail MCP Server

AI agents use gmail.addLabels 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.addLabels needs a policy

Adding labels is a metadata modification that creates or assigns organizational tags to emails. This is reversible (labels can be removed), has minimal blast radius (affects only message organization), and does not delete data, execute code, or move money. It fits squarely in the Write category with low severity.

From the tool's definition Tool name explicitly states 'addLabels' and description confirms 'Add labels to messages or threads' — a reversible modification operation. Labels can be removed or changed, making this a Write operation rather than Read or Destructive.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

gmail.addLabels Rate-limited

gmail.addLabels 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.addLabels": {
      "limits": [
        {
          "counter": "gmail.addlabels_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 MCP Server, so you can run agents against it safely.

FAQ

Questions about gmail.addLabels

What does the gmail.addLabels tool do? +

Add labels to messages or threads. Requires gmail.labels scope. 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.addLabels? +

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

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

Can I rate-limit gmail.addLabels? +

Yes. Add a rate_limit block to the gmail.addLabels 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.addLabels completely? +

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

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