cloud_send_message · Vestaboard MCP Server MCP

WHAT IT DOES

What cloud_send_message does on Vestaboard MCP Server

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

WHY IT NEEDS A POLICY

Why cloud_send_message needs a policy

This tool modifies data on a Vestaboard display—what is currently shown on the device—making it a Write operation rather than Read. While it doesn't delete or move money, misuse could cause reputational or operational harm (e.g., an AI agent sending inappropriate messages to a public display).

From the tool's definition Tool description states 'Send a message to the Vestaboard' which creates/modifies the content displayed on a physical device. The name 'send_message' and description confirm this is a write operation that changes the state of the display.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

cloud_send_message Rate-limited

cloud_send_message 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": {
    "cloud_send_message": {
      "limits": [
        {
          "counter": "cloud_send_message_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 Vestaboard MCP Server, so you can run agents against it safely.

FAQ

Questions about cloud_send_message

What does the cloud_send_message tool do? +

Send a message to the Vestaboard using the cloud API. It is categorised as a Write tool in the Vestaboard 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 cloud_send_message? +

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

What risk level is cloud_send_message? +

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

Can I rate-limit cloud_send_message? +

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

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

cloud_send_message is provided by the Vestaboard MCP Server MCP server (lintility/vestaboard-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.