Simulate mouse wheel movement to shift the page vertically or horizontally, enabling UI interaction tests in Electron apps.
Scroll the page using mouse wheel
| Name | Required | Description | Default |
|---|---|---|---|
| deltaX | No | Horizontal scroll amount (positive = right, negative = left) | |
| deltaY | No | Vertical scroll amount (positive = down, negative = up) |
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It discloses the input mechanism (mouse wheel) but not defaults for zero/omitted deltas, whether scroll is instant or animated, whether it waits for scroll to settle, or whether scrolling is bounded by the viewport.
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 short sentence with no filler, front-loaded with the verb and target. It is appropriately sized, though minimal.
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 mutation-ish interaction tool with zero annotations and no output schema, the description omits the behavior an agent needs: default magnitudes when deltas are omitted (both params are optional), scrolling semantics, and any effect on page state. Adequate only at the very lowest bar.
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?
Schema coverage is 100% and both parameters are documented with sign conventions in the schema itself. The description adds nothing beyond what the schema provides, so baseline 3 is appropriate.
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?
States a specific verb (Scroll) and resource (the page), and notes the mechanism (mouse wheel). It is distinguishable from scrollTo and scrollIntoView by name, but the description doesn't explain how it differs from those siblings.
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?
No when-to-use or when-not-to-use guidance. With siblings scrollTo, scrollIntoView, mouseMove, and mouseDown all in the same family, an agent has no stated basis for choosing wheel-scroll over those alternatives.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.