Scroll web pages or elements into view using a CSS selector or element reference, with adjustable horizontal and vertical scroll deltas.
Scroll the page or scroll an element into view.
| Name | Required | Description | Default |
|---|---|---|---|
| ref | No | Element reference to scroll into view (@1, @2...) | |
| delta_x | No | Horizontal scroll delta | |
| delta_y | No | Vertical scroll delta (positive=down, negative=up) | |
| selector | No | CSS selector to scroll into view |
Changes observed during successful MCP inspections.
v0.8.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden, yet it adds nothing beyond the purpose sentence. It does not state scroll behavior (instant vs smooth), where the scroll is applied (page vs container), what happens when ref/selector match nothing, or how the two modes interact with delta_x/delta_y.
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 front-loaded sentence that covers both operating modes with no waste. It is appropriately sized for a simple action tool, though it is sparse enough that brevity shades into under-specification.
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?
With no annotations and no output schema, the description is the only place behavioral context could live, and it stays thin. The 100% schema coverage rescues it to a minimum-viable level, but the two-mode usage model is left for the agent to piece together.
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 100%, so all four parameters are already documented in the schema, setting the baseline at 3. The description faintly maps the two modes (page scroll vs element-into-view) but provides no format or interaction details beyond the schema.
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 both resources (the page, or an element into view). An agent can tell this is a viewport-manipulation tool and not one of the navigation or inspection siblings. It stops short of naming any alternative, but the purpose itself 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?
There is no when-to-use context, no prerequisites, and no routing to alternatives such as browser_snapshot or browser_find_in_page. The agent must infer entirely from the name that this is the tool for moving the viewport.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.