usable-browser-agent-free

browser_scroll

Scroll a webpage or specific scrollable element to a specified position. Supports directional scrolling or jumping to top/bottom.

Instructions

Scroll the page or a specific scrollable container. Pass a ref to scroll that container (inner panes, virtualized/infinite lists); omit it to scroll the window. Use to='bottom' to jump to the end (e.g. trigger infinite-scroll loading).

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "browser_scroll"
  }
}

Input Schema

Name	Required	Description
`to`	No	Jump to the top or bottom of the target.
`ref`	No	Scroll this container (or, with no direction/to, just reveal it).
`amount`	No
`direction`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.7.0Sep 9, 2026

TDQS

A3.7/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the burden. It discloses that ref with no direction/to just reveals the container, and that to='bottom' jumps to the end. However, it does not mention smooth vs. instant scrolling, focus changes, or the effect of combining direction and amount. Some behavioral nuance is covered, but not exhaustively.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Three concise sentences that front-load the main action, then provide practical usage details. No fluff or repetition; every sentence contributes to understanding when and how to use the tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Despite having no output schema and no annotations, the description leaves out critical information about the interaction between direction, amount, and to. It doesn't explain what happens when direction is combined with to, or how amount scales the scroll. For a tool with 4 parameters, this is incomplete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 50%; only to and ref have schema descriptions. The description adds meaning for ref (reveal behavior) and to (infinite-scroll trigger), but says nothing about the 'amount' and 'direction' parameters, which are entirely undocumented in both schema and description. This fails to compensate for the low coverage on half the parameters.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool scrolls the page or a scrollable container, with a specific verb and resource. It differentiates from siblings because no other sibling tool is for scrolling; it also distinguishes between window and container scrolling via ref.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides explicit guidance on when to pass a ref (to scroll a container like inner panes or virtualized lists) versus omit it (scroll the window). Also explains using to='bottom' to trigger infinite-scroll loading. No exclusions are given, but no direct alternatives exist among siblings, so the context is sufficient.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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