Scroll

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

Annotations declare readOnlyHint=false and openWorldHint=true, so the tool may mutate or cause side effects. The description does not disclose what side effects occur (e.g., scroll position changes are visible to user) or any potential navigation side effects. It adds a small detail about delta direction (positive = down) but misses the broader behavioral implications of openWorldHint.

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?

One concise sentence covers the two main modes, with the key condition ('when no element is given') included. It is front-loaded and to the point, though it could add a brief note about parameter precedence without much length.

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?

With 8 parameters and no output schema, the description does not explain how the different locator strategies interact (ref vs css vs role/name), nor what happens if multiple are provided. It also doesn't note that refs are only valid for the current page state, though that is in the schema. The description adds the core mode distinction but leaves open questions about parameter precedence and error behavior.

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%, so every parameter is documented in the schema. The description adds the relationship between delta scrolling and element scrolling (dy positive = down), but does not explain interactions between parameters (e.g., dx/dy together vs ref/css/role/name). Baseline 3 is appropriate since schema covers most semantics.

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 (scrolls) with two modes: into view by element, or pixel delta. It distinguishes between element-based and delta-based scrolling, but does not explicitly contrast with sibling navigation tools like browser_navigate or browser_go_back, so it could be clearer about its unique role.

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 implies when to use delta vs element scrolling ('when no element is given') and mentions the element ref is preferred. However, it does not provide explicit when-not-to-use guidance or name alternatives (e.g., browser_navigate for page-level jumps). It gives clear context for the two modes but no exclusions.

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