send_url_to_device · Lyceum MCP: Risk & Policy

WHAT IT DOES

What send_url_to_device does on Lyceum

AI agents invoke send_url_to_device to trigger actions in Lyceum. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why send_url_to_device needs a policy

This tool performs multiple chained operations: fetching a URL, converting content, and pushing it to an external device. It triggers an external operation (sending to a device) whose effects depend on arguments. It doesn't merely read or write library data, nor is it destructive or financial — it executes a workflow that interacts with an external e-reader device.

From the tool's definition Fetch a URL, convert the article to an epub, and send it directly to an e-reader device without saving to the library

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

send_url_to_device Rate-limited

send_url_to_device stays usable, but rate-capped — a runaway agent can't fire it dozens of times 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_url_to_device": {
      "limits": [
        {
          "counter": "send_url_to_device_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Lyceum, so you can run agents against it safely.

FAQ

Questions about send_url_to_device

What does the send_url_to_device tool do? +

Fetch a URL, convert the article to an epub, and send it directly to an e-reader device without saving to the library. It is categorised as a Execute tool in the Lyceum MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on send_url_to_device? +

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

What risk level is send_url_to_device? +

send_url_to_device is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit send_url_to_device? +

Yes. Add a rate_limit block to the send_url_to_device 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_url_to_device completely? +

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

send_url_to_device is provided by the Lyceum MCP server (matthewp/lyceum). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.