get_preview_url · Prowpt MCP Server MCP: Risk & Policy

WHAT IT DOES

What get_preview_url does on Prowpt MCP Server

AI agents invoke get_preview_url to trigger actions in Prowpt MCP Server. 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 get_preview_url needs a policy

While the tool returns a URL (read-like), it first triggers a build process (bundle compilation), which constitutes executing an external operation. The blast radius is medium since a misused build could consume resources or produce unintended artifacts, but it does not modify persistent data directly.

From the tool's definition 'Build a preview bundle and return the URL' — the tool actively builds/compiles a bundle, which is an execution operation, not merely a read

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

get_preview_url Rate-limited

get_preview_url 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": {
    "get_preview_url": {
      "limits": [
        {
          "counter": "get_preview_url_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 Prowpt MCP Server, so you can run agents against it safely.

FAQ

Questions about get_preview_url

What does the get_preview_url tool do? +

Build a preview bundle and return the URL. It is categorised as a Execute tool in the Prowpt MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on get_preview_url? +

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

What risk level is get_preview_url? +

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

Can I rate-limit get_preview_url? +

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

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

get_preview_url is provided by the Prowpt MCP Server MCP server (prowptai/prowpt-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.