Scroll the mouse wheel up or down by a specified amount, optionally at exact screen coordinates, to navigate pages or pan content during desktop automation.
Scroll the mouse wheel. Positive amount scrolls up, negative down. Optionally at specific coordinates (x, y).
| Name | Required | Description | Default |
|---|---|---|---|
| x | No | ||
| y | No | ||
| amount | No |
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are present, so the description carries the full burden. It explains positive/negative amount direction and coordinate options, but does not disclose behavior when coordinates are omitted (presumably current cursor position), whether scrolling at coordinates moves the pointer, or any return value. Core behavior is covered, but operational details are missing.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
A single concise sentence that front-loads the core action and includes the most important semantic details without redundancy. Every clause earns its place.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple input tool with no output schema, the description covers action, direction, and coordinates. However, it leaves null-coordinate behavior and coordinate-frame assumptions implicit. With zero annotations, these gaps are meaningful but not critical for a basic scroll operation.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The description adds meaning beyond the schema by explaining that positive amount scrolls up, negative down, and that x/y are optional coordinates. The schema only provides types and defaults. It does not define the unit of amount or the coordinate system, but the added semantics justify above baseline.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description states a specific verb and resource: 'Scroll the mouse wheel,' and clarifies direction semantics and optional coordinates. This distinguishes it from sibling mouse tools like click or move_mouse, though it does not explicitly name them.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
Usage is implied: an agent would use this when a scroll action is needed. However, there is no explicit guidance on when not to use it or which alternative tools to prefer, such as drag or keyboard-based scrolling. No exclusions or conditions are provided.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.