scroll

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

The description discloses one real behavioral trait beyond annotations: lazy-loaded content materializes only in the subsequent snapshot, which shapes the follow-up call. It does not clarify that scroll position persists across calls (relevant given readOnlyHint=false) or how to return to the top, so transparency is partial.

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 front-loaded sentence with the verb, direction, unit, and the follow-up caveat in parentheses. Every clause earns its place and nothing is padded.

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 three-parameter viewport tool with no output schema, this covers the essentials plus the lazy-load follow-up behavior. The main shortfall is silence on scroll scope (whole page vs. container) and whether position is retained between calls.

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 carry parameter meaning. It covers direction implicitly via the quoted "up"/"down" and amount via "pixels", but never states the valid values as a closed set, nor the defaults (down, 800), and says nothing about session_id.

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?

States a specific verb (scroll) and resource (the page) with the two controlling parameters (direction, amount in pixels). It is clearly separable from siblings like navigate, snapshot, and find, though it does not name those alternatives explicitly.

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 parenthetical hints at the workflow (lazy-loaded content shows up in the next snapshot), which implies when to call it, but there is no explicit when-to-use, when-not-to-use, or named alternative such as navigating directly or using find to jump to an element.

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