Scroll

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

Annotations already provide idempotentHint and destructiveHint, so the bar is lower. The description adds useful behavioral context by stating that page scrolls report scrollY, pageHeight, and viewport, letting the agent know how much scroll remains. No contradiction with annotations exists.

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?

The description is two sentences with no filler. It front-loads the main purpose and follows with a useful behavioral detail about returned metrics, making every sentence earn 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?

With six parameters, full schema coverage, and no output schema, the description covers the core page-scroll return value but does not describe the return shape for element scrolls or the verbose output mode. This leaves a minor gap, but overall the definition is sufficiently complete for an agent to call the tool correctly.

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 schema describes all six parameters in full, so the description does not need to explain them. The description adds no parameter-level meaning beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 the tool scrolls the page or scrolls an element into view, with a specific verb and resource. It is unambiguous and readable, but it does not explicitly distinguish it from sibling tools that could also scroll (e.g., press_key or execute_javascript), so it misses full sibling differentiation.

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?

There is no guidance about when to use this tool versus alternatives, nor any exclusions or preferred conditions. The description simply describes what it does, leaving the agent to infer when it should be selected over other sibling navigation or input tools.

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