Scrolls a browser page by X/Y offsets and optionally brings a snapshot ref or CSS selector target into view before scrolling.
Scroll the page, optionally bringing a target into view first.
| Name | Required | Description | Default |
|---|---|---|---|
| deltaX | No | ||
| deltaY | No | ||
| pageId | No | Defaults to the active page | |
| target | No | Snapshot ref (e12) or unique CSS selector | |
| sessionId | No | Defaults to the active session |
Changes observed during successful MCP inspections.
v2026.10.24Input schema / properties / pageId / descriptionPrevious value: -"Stable page ID; defaults to the session active page"New value: +"Defaults to the active page"Input schema / properties / sessionId / descriptionPrevious value: -"Optional session ID; defaults to this MCP client active session"New value: +"Defaults to the active session"Input schema / properties / target / descriptionPrevious value: -"Snapshot ref such as e12, aria-ref=e12, or a unique CSS selector"New value: +"Snapshot ref (e12) or unique CSS selector"v2026.8.14Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden, yet it does not disclose scroll direction semantics, whether scrolling is instant or smooth, wait behavior, failure modes for missing targets, or whether the page must be loaded.
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?
The single sentence is front-loaded and contains no filler. It is concise, though the brevity borders on under-specification for a five-parameter browser tool.
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?
The tool has five parameters, only 60% schema description coverage, no annotations, and no output schema. The description is too sparse to fully prepare an agent for invocation, especially around deltaX/deltaY semantics and scroll behavior.
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 only 60%, and the description does not explain deltaX or deltaY at all. It adds some meaning for target, but that parameter is already documented in the schema as a snapshot ref or CSS selector.
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 action and resource: scrolling the page, with optional target-into-view behavior. It is clear, but it does not distinguish this tool from nearby browser interaction tools such as snapshot, wait_for, or click.
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 implies that a target can be brought into view first, but gives no explicit guidance on when to use scrolling versus other browser tools, when to omit target, or when target is required for offscreen elements.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.