scroll

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

With no annotations provided, the description carries the full burden and discloses a side effect ('modifies DOM scroll position (observable but reversible)'), a prerequisite, and a return value. This is useful transparency, though it does not go into edge cases like element-not-found failure or lazy-loading behavior.

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?

Four concise sentences front-load the primary action, then cover side effects, prerequisites, return value, use case, and alternatives with no wasted words. Every sentence earns its place.

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 six-parameter tool with no output schema or annotations, the description gives enough context to use it correctly: purpose, modes, side effects, return confirmation, and relevant alternatives. It could add more about failure modes, but the schema covers parameter-level behavior comprehensively.

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?

The parameter schema already provides 100% coverage with detailed descriptions for each parameter, so the baseline is 3. The description adds a useful high-level mapping of pixel offset, pages, and selector to the underlying parameters, but does not add meaning beyond what the schema already documents.

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 a specific verb and resource ('Scrolls the page') and enumerates the three distinct modes: pixel offset, viewport pages, and element selector. It also distinguishes itself from sibling tools by naming click_element and evaluate_js as alternatives.

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 explicitly says when to use this tool ('navigate within long pages or bring elements into view') and names alternatives with their purpose ('click_element' for click-triggered scroll, 'evaluate_js' for custom scroll logic). It also provides a prerequisite: requires an active Chrome tab with content.

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