scroll_by

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

No annotations are present, so the description carries the burden. It explains that scrolling is by pixels and direction sign, but fails to disclose behavior at page boundaries, whether scrolling is smooth or instant, or if negative values are allowed (implied but not explicit). For a simple action, this is adequate but could be improved.

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 sentence that is perfectly front-loaded with the core purpose. No unnecessary words. Every part is essential.

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 is simple with no output schema. The description covers the basic action and direction sign. However, it doesn't mention that x defaults to 0 and y to 300 (though schema shows defaults), nor explicitly state negative values for opposite direction. Slightly incomplete but sufficient for a straightforward tool.

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 100% with descriptions for x and y. The description adds the interpretation 'positive = down/right' which is not in the schema, clarifying sign conventions. This adds meaningful value beyond the schema's parameter descriptions.

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 clearly states 'Scroll the page by a given number of pixels' with verb and resource, and adds direction meaning 'positive = down/right'. Among sibling tools like scroll_to_element, scroll_to_top, scroll_to_bottom, this one is uniquely identified as pixel-based scrolling.

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?

The description provides no guidance on when to use this tool versus alternatives like scroll_to_element or scroll_to_top. There is no mention of prerequisites, when-not-to-use, or contrasts with other scrolling tools.

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