Skip to main content
Glama
Sign In
Browser MCP

Browser MCP

by drisplabs
OverviewSchemaSourceRelated ServersDiscussionsAdmin
TypeScript
Local

Wheel

wheel

Dispatch mouse wheel events at specific coordinates to scroll vertically or horizontally, or zoom with the Control modifier.

Instructions

Dispatch a mouse wheel event at specific coordinates. Use for scroll-to-zoom (with Control modifier) or horizontal scrolling.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "x": "<x>",
      "y": "<y>",
      "deltaY": "<deltaY>"
    },
    "name": "wheel"
  }
}

Input Schema

NameRequiredDescriptionDefault
xYesX coordinate where the wheel event is dispatched.
yYesY coordinate where the wheel event is dispatched.
eidNoOptional element ID. When provided, x/y coordinates are relative to the element top-left corner.
deltaXNoHorizontal scroll delta in pixels. Positive scrolls right.
deltaYYesVertical scroll delta in pixels. Positive scrolls down, negative scrolls up. For zoom: negative typically zooms in, positive zooms out.
page_idNoThe ID of the page.
modifiersNoModifier keys to hold during the wheel event (e.g., Control for zoom).

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv4.6.4

TDQS

A4/5.0
Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description mentions behavioral effects (zoom with Control, horizonal scroll) but does not elaborate on default behavior, such as what happens without modifiers (vertical scroll) or event dispatching details. Given no annotations, this is adequate but leaves some ambiguity.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences, front-loading the primary action. Every word serves a purpose, with no redundancy or filler. It efficiently conveys both the core function and primary use cases.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's simplicity and the presence of sibling tools like 'scroll' and 'scroll_to', the description adequately captures its distinct purpose. However, it does not explicitly differentiate from those tools or explain the return value, though this is minor for an event dispatch action.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema covers 100% of parameters, so baseline is 3. The description adds context by mentioning 'Control modifier' and 'horizontal scrolling,' which relate to parameters 'modifiers' and 'deltaX', but does not provide additional semantic details beyond what the schema already documents.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool dispatches a mouse wheel event at specific coordinates, with explicit use cases for scroll-to-zoom and horizontal scrolling. This distinguishes it from sibling tools like 'scroll' and 'scroll_to' by specifying the exact event type and coordinate-based nature.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides two explicit use cases: 'scroll-to-zoom (with Control modifier)' and 'horizontal scrolling'. It implies when these scenarios apply but does not explicitly state when not to use this tool or mention alternatives like 'scroll' or 'hover'.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server

Other Tools