# Scroll

Scroll action, Scroll the page or a scrollable element to browse content. This is the preferred way to scroll on all platforms, including mobile. Supports scrollToBottom/scrollToTop for boundary navigation. Default: direction down, scrollType singleAction, distance null.. Parameters: scrollType? (enum('singleAction', 'scrollToBottom', 'scrollToTop', 'scrollToRight', 'scrollToLeft')) - The scroll behavior: "singleAction" for a single scroll action, "scrollToBottom" for scrolling all the way to the bottom by rapidly scrolling 5-10 times (skipping intermediate content until reaching the bottom), "scrollToTop" for scrolling all the way to the top by rapidly scrolling 5-10 times (skipping intermediate content until reaching the top), "scrollToRight" for scrolling all the way to the right by rapidly scrolling multiple times, "scrollToLeft" for scrolling all the way to the left by rapidly scrolling multiple times; direction? (enum('down', 'up', 'right', 'left')) - The direction to scroll. Only effective when scrollType is "singleAction".; distance? (number) - The distance in pixels to scroll; locate? (object) - Describe the target element to be scrolled on, like "the table" or "the list" or "the content area" or "the scrollable area". Do NOT provide a general intent like "scroll to find some element"

Agent View of the PolicyLayer registry record for `Scroll`. HTML page: https://policylayer.com/tools/android/scroll

## Facts

- Tool: `Scroll`
- Server: Android (`@midscene/android-mcp`) — https://policylayer.com/tools/android.md
- Install: `npx -y @midscene/android-mcp`
- Homepage: https://www.npmjs.com/package/@midscene/android-mcp
- Risk category: Execute (High risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 10
- Recommended policy verdict: Rate-limited

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `locate` | object | no | Describe the target element to be scrolled on, like "the table" or "the list" or "the content area" or "the scrollable area". Do NOT provide a general intent li |
| `distance` | number | null | no | The distance in pixels to scroll |
| `direction` | string | no | The direction to scroll. Only effective when scrollType is "singleAction". |
| `scrollType` | string | no | The scroll behavior: "singleAction" for a single scroll action, "scrollToBottom" for scrolling all the way to the bottom by rapidly scrolling 5-10 times (skippi |
| `android.deviceId` | string | no | Android device ID (from adb devices) |
| `android.useScrcpy` | boolean | no | Enable scrcpy accelerated screenshots |
| `android.aiActContext` | string | no | Background knowledge passed to aiAct. Default: no extra context. |
| `android.waitAfterAction` | number | no | Wait time in milliseconds after each action execution. Default: 300ms. |
| `android.replanningCycleLimit` | integer | no | Maximum number of replanning cycles for aiAct. Default: model adapter default. |
| `android.screenshotShrinkFactor` | number | no | Screenshot shrink factor before sending images to AI. Default: 1; high values may reduce recognition quality, especially on mobile. |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "Scroll",
    "arguments": {}
  }
}
```

## Why Scroll is rated High

This tool triggers a physical UI interaction on an Android device (scrolling), which is an external operation that depends on arguments. It falls under Execute as it performs browser/device actions rather than simply reading or writing data. Misuse could cause unintended navigation but blast radius is moderate.

From the tool's own definition: "Scroll action, Scroll the page or a scrollable element to browse content... Supports scrollToBottom/scrollToTop for boundary navigation..."

Risk signals: High parameter count (15 properties)

## Use case

AI agents invoke Scroll to trigger actions in Android. 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.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Android:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "Scroll": {
      "limits": [
        {
          "counter": "scroll_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Android (22)

- `ClearInput` — Destructive — https://policylayer.com/tools/android/clearinput.md
- `act` — Execute — https://policylayer.com/tools/android/act.md
- `android_connect` — Execute — https://policylayer.com/tools/android/android-connect.md
- `AndroidBackButton` — Execute — https://policylayer.com/tools/android/androidbackbutton.md
- `AndroidHomeButton` — Execute — https://policylayer.com/tools/android/androidhomebutton.md
- `AndroidRecentAppsButton` — Execute — https://policylayer.com/tools/android/androidrecentappsbutton.md
- `CursorMove` — Execute — https://policylayer.com/tools/android/cursormove.md
- `DoubleClick` — Execute — https://policylayer.com/tools/android/doubleclick.md
- `DragAndDrop` — Execute — https://policylayer.com/tools/android/draganddrop.md
- `KeyboardPress` — Execute — https://policylayer.com/tools/android/keyboardpress.md
- `Launch` — Execute — https://policylayer.com/tools/android/launch.md
- `LongPress` — Execute — https://policylayer.com/tools/android/longpress.md
- `Pinch` — Execute — https://policylayer.com/tools/android/pinch.md
- `PullGesture` — Execute — https://policylayer.com/tools/android/pullgesture.md
- `RunAdbShell` — Execute — https://policylayer.com/tools/android/runadbshell.md
- `Swipe` — Execute — https://policylayer.com/tools/android/swipe.md
- `Tap` — Execute — https://policylayer.com/tools/android/tap.md
- `Terminate` — Execute — https://policylayer.com/tools/android/terminate.md
- `take_screenshot` — Read — https://policylayer.com/tools/android/take-screenshot.md
- `android_disconnect` — Write — https://policylayer.com/tools/android/android-disconnect.md
- `assert` — Write — https://policylayer.com/tools/android/assert.md
- `Input` — Write — https://policylayer.com/tools/android/input.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=android · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/android