Move the Affinity design canvas up or down using a positive or negative amount, optionally targeting x/y from the last screenshot to reveal off-screen content.
Scroll: positive = up, negative = down. Pass x, y (last screenshot) to scroll over a specific area.
| Name | Required | Description | Default |
|---|---|---|---|
| x | No | ||
| y | No | ||
| amount | Yes | ||
| screenshot_after | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full disclosure burden. It discloses scroll direction semantics but says nothing about side effects such as the automatic screenshot_after behavior (default true in schema), whether scrolling requires a focused window, or what the tool returns.
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?
Two short sentences with the important sign convention front-loaded and no filler. It is terse to the point of being telegraphic ('Pass x, y (last screenshot)'), but every phrase carries information.
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 four-parameter tool with no annotations and no output schema, the description leaves too much uncovered: the screenshot_after parameter, magnitude expectations for amount, and the effect of omitting x/y are all unaddressed.
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 description coverage is 0%, so the description must compensate, and it does add real meaning for amount (positive = up, negative = down) and x/y (scroll over a specific area). It omits screenshot_after entirely and gives no units or magnitude guidance for amount, leaving one of four parameters undocumented.
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') and immediately defines the sign convention of the amount, so an agent knows exactly what the tool does. It does not explicitly distinguish itself from siblings like drag or press_key, but the action is unambiguous.
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?
It gives one conditional usage rule — pass x, y (last screenshot) to scroll within a specific area — which implies the default is scrolling the whole viewport. However, it never says when to prefer scroll over alternatives such as press_key or drag, so guidance is only implied.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.