send_multicast · LineWhiz MCP: Risk & Policy

WHAT IT DOES

What send_multicast does on LineWhiz

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

WHY IT NEEDS A POLICY

Why send_multicast needs a policy

This tool modifies external state by delivering messages to multiple users, making it a Write operation. Severity is high because an AI agent with unrestricted use could spam many users simultaneously (up to 500 in one call), damaging the LINE Official Account's reputation and violating user expectations.

From the tool's definition Tool performs 'send_multicast' which sends text messages to multiple users (up to 500 user IDs). This is a write operation that creates/transmits new messages to users.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

send_multicast Rate-limited

send_multicast 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": {
    "send_multicast": {
      "limits": [
        {
          "counter": "send_multicast_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 LineWhiz, so you can run agents against it safely.

FAQ

Questions about send_multicast

What does the send_multicast tool do? +

Send a text message to multiple users at once (max 500 user IDs). It is categorised as a Write tool in the LineWhiz MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on send_multicast? +

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

What risk level is send_multicast? +

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

Can I rate-limit send_multicast? +

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

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

send_multicast is provided by the LineWhiz MCP server (kinzen-dev/linewhiz). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.