set_add · Amazon MQ MCP Server MCP: Risk & Policy

WHAT IT DOES

What set_add does on Amazon MQ MCP Server

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

WHY IT NEEDS A POLICY

Why set_add needs a policy

This tool modifies data by adding a member to a set, which is a write operation. It has medium severity because unauthorized addition of members to sets in an MQ broker context could affect message routing, permissions, or consumer groups, but the change is reversible.

From the tool's definition Tool name 'set_add' with description 'Add member to set' indicates creation/modification of set membership without deletion or irreversible changes. The action is reversible (members can be removed).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_add Rate-limited

set_add 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": {
    "set_add": {
      "limits": [
        {
          "counter": "set_add_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 Amazon MQ MCP Server, so you can run agents against it safely.

FAQ

Questions about set_add

What does the set_add tool do? +

Add member to set. It is categorised as a Write tool in the Amazon MQ 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 set_add? +

Register the Amazon MQ MCP Server MCP server in PolicyLayer and add a rule for set_add: 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 Amazon MQ MCP Server. Nothing to install.

What risk level is set_add? +

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

Can I rate-limit set_add? +

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

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

set_add is provided by the Amazon MQ MCP Server MCP server (awslabs.amazon-mq-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.