add_members · Groupme MCP: Risk & Policy

WHAT IT DOES

What add_members does on Groupme

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

WHY IT NEEDS A POLICY

Why add_members needs a policy

Adding members to a group is a reversible write operation—it modifies group membership state but does not destroy data or execute arbitrary code. The description is empty, slightly lowering confidence, but the name and server context clearly indicate membership modification (Write).

From the tool's definition Tool name 'add_members' indicates creating or adding user relationships to a group. The server description confirms it 'manage[s] groups, members' through GroupMe API integration.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_members Rate-limited

add_members 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_members": {
      "limits": [
        {
          "counter": "add_members_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 Groupme, so you can run agents against it safely.

FAQ

Questions about add_members

What does the add_members tool do? +

add_members. It is categorised as a Write tool in the Groupme 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_members? +

Register the Groupme MCP server in PolicyLayer and add a rule for add_members: 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 Groupme. Nothing to install.

What risk level is add_members? +

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

Can I rate-limit add_members? +

Yes. Add a rate_limit block to the add_members 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_members completely? +

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

add_members is provided by the Groupme MCP server (kalebjs/groupme-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.