scroll_page

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

With no annotations, the description carries the behavioral burden. It discloses that scrolling reports the new position, describes the scan_page interplay, and states defaults for 'to' and timeout. It does not explain timeout semantics or session_id behavior, but the core side effects and return information are present.

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 tight sentences deliver the core action, the relationship to scan_page, and all relevant parameter guidance. There is no filler or repetition of schema 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 simple scroll operation with no required parameters and an output schema, the description covers the main usage workflow and the primary parameter. It could add a bit more context around timeout and session_id, but nothing critical is missing for correct invocation.

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 0%, so the description must add meaning. It does this well for 'to' by enumerating bottom/top, pixel offsets, and CSS selectors, and it mentions the timeout default. However, it does not explain what timeout applies to or what session_id means, leaving a gap for one parameter.

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 opens with a specific verb and resource: 'Scroll the page and report the new position.' It clearly establishes what the tool does and distinguishes it from related navigation tools like open_url or execute_js.

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 explicitly connects to scan_page's ±5000px limitation and gives a concrete workflow: scan, then scroll, then scan again. It also explains the accepted forms for the 'to' parameter, making when and how to use the tool clear.

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