add_group_user · Looker MCP Server MCP: Risk & Policy

WHAT IT DOES

What add_group_user does on Looker MCP Server

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

WHY IT NEEDS A POLICY

Why add_group_user needs a policy

The tool creates or modifies group membership data (adding a user to a group). This is a reversible Write operation—the user can be removed from the group later. While it has administrative implications affecting access control and permissions, it does not delete data (Destructive), execute arbitrary code (Execute), or move money (Financial).

From the tool's definition Tool description: 'Add a user to a group.' This modifies group membership, a reversible administrative operation. The server context indicates user administration capabilities ('administering users').

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_group_user Rate-limited

add_group_user 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_group_user": {
      "limits": [
        {
          "counter": "add_group_user_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 Looker MCP Server, so you can run agents against it safely.

FAQ

Questions about add_group_user

What does the add_group_user tool do? +

Add a user to a group. It is categorised as a Write tool in the Looker 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_group_user? +

Register the Looker MCP Server MCP server in PolicyLayer and add a rule for add_group_user: 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 Looker MCP Server. Nothing to install.

What risk level is add_group_user? +

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

Can I rate-limit add_group_user? +

Yes. Add a rate_limit block to the add_group_user 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_group_user completely? +

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

add_group_user is provided by the Looker MCP Server MCP server (ultrathink-solutions/looker-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.