add_role_members · HAP MCP Server MCP: Risk & Policy

WHAT IT DOES

What add_role_members does on HAP MCP Server

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

WHY IT NEEDS A POLICY

Why add_role_members needs a policy

This tool creates or modifies role membership associations, which is a Write operation (reversible data modification). While role management touches access control, the operation itself is not destructive (members can be removed) nor financial.

From the tool's definition Tool name 'add_role_members' and description 'Add members to a role' indicate modification of role membership data. This is a reversible write operation that alters access control assignments.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_role_members Rate-limited

add_role_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_role_members": {
      "limits": [
        {
          "counter": "add_role_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 HAP MCP Server, so you can run agents against it safely.

FAQ

Questions about add_role_members

What does the add_role_members tool do? +

Add members to a role. It is categorised as a Write tool in the HAP 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_role_members? +

Register the HAP MCP Server MCP server in PolicyLayer and add a rule for add_role_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 HAP MCP Server. Nothing to install.

What risk level is add_role_members? +

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

Can I rate-limit add_role_members? +

Yes. Add a rate_limit block to the add_role_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_role_members completely? +

Set action: deny in the PolicyLayer policy for add_role_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_role_members? +

add_role_members is provided by the HAP MCP Server MCP server (mingdaocloud/hap-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.