add_delegate · Gmail MCP Server MCP: Risk & Policy

WHAT IT DOES

What add_delegate does on Gmail MCP Server

AI agents use add_delegate 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 add_delegate needs a policy

Adding a delegate grants another user access to the Gmail account, which is a write/configuration operation that creates a new permission relationship. This is highly sensitive because it gives a third party access to read, send, and manage emails on behalf of the account owner — a significant security and privacy risk if misused.

From the tool's definition Adds a delegate to the specified account

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_delegate Rate-limited

add_delegate 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": {
    "add_delegate": {
      "limits": [
        {
          "counter": "add_delegate_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 add_delegate

What does the add_delegate tool do? +

Adds a delegate to the specified account. 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 add_delegate? +

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

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

Can I rate-limit add_delegate? +

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

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

add_delegate is provided by the Gmail MCP Server MCP server (nk900600/gmail-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

// THE FULL RECORD

add_delegate is one line of Gmail MCP Server's registry record.

The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.

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