scroll

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

With no annotations, the description carries the full burden, and it does add real behavioral context: units are CSS pixels, it reports before/after movement, it does not guarantee lazy-load completeness, and it only works on the main document. However, it omits whether the call blocks, how the movement report is shaped, and any timeout/permission implications.

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?

Three terse clauses with no filler, and the primary scope constraint (main-document) leads. The telegraphic style is efficient but borders on under-specified fragments.

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 4-param tool with no annotations and no output schema, the description covers scope, units, and rough return semantics, which is decent. It still leaves the shape of the 'before/after movement' report and timeout behavior unaddressed, so it is adequate but not complete.

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 50%, with tab_id and timeout documented in-schema while amount and direction are bare. The description's 'CSS pixels' clause usefully clarifies the unit for the amount parameter, but it adds nothing for direction and leaves amount's range/semantics largely to 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?

The description conveys that this performs a wheel/scroll input on the main document, but the phrasing 'One main-document native wheel input' is cryptic and never states a clean verb+resource like 'scroll the page'. It does implicitly separate itself from inner-pane scrolling, giving partial sibling differentiation against act/observe/screenshot.

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 explicit when-to-use guidance and no mention of alternatives such as act or observe for interacting with the page. The 'Inner panes unsupported' clause implies a scope exclusion but is not framed as usage guidance.

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