scroll_until_visible · Phantom MCP: Risk & Policy

WHAT IT DOES

What scroll_until_visible does on Phantom

AI agents invoke scroll_until_visible to trigger actions in Phantom. 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 scroll_until_visible needs a policy

This tool performs a UI automation action (scrolling) on a mobile device or emulator until a UI element is visible. It triggers external device interactions whose effects depend on arguments (direction, target element). The description is truncated ('jusqu') but the tool name and server context make clear it performs device control actions.

From the tool's definition 'scroll_until_visible' - scrolls in a direction until an element becomes visible; triggers external operations (UI interaction) on iOS simulators, Android emulators, or real devices

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

scroll_until_visible Rate-limited

scroll_until_visible 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": {
    "scroll_until_visible": {
      "limits": [
        {
          "counter": "scroll_until_visible_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 Phantom, so you can run agents against it safely.

FAQ

Questions about scroll_until_visible

What does the scroll_until_visible tool do? +

Scroll vers le bas (ou la direction choisie) jusqu. It is categorised as a Execute tool in the Phantom MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on scroll_until_visible? +

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

What risk level is scroll_until_visible? +

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

Can I rate-limit scroll_until_visible? +

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

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

scroll_until_visible is provided by the Phantom MCP server (nthimpulse/phantom-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.