scroll

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

With no annotations, the description carries the full burden of behavioral disclosure. It explicitly says the tool scrolls and returns a new snapshot, covering the core action and output. It also documents defaults for direction and amount. It does not mention edge cases or side effects, but for a simple scrolling operation, this is sufficient.

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 extremely concise: one sentence for the action and output, followed by a compact list of parameter explanations. Every piece of information is necessary and directly relevant, and the structure is well-organized with the main purpose front-loaded.

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?

Given the tool's low complexity (three optional parameters) and the presence of an output schema, the description is complete. It explains all parameters, states the output (snapshot), and does not need to elaborate on return structure. It is self-sufficient for an agent to invoke 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 description provides plain-language explanations for all three parameters: direction (allowed values), amount (pixels), and session_id (session to act on). The schema only has titles and defaults, so the description adds essential meaning and compensates for the 0% schema description coverage.

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's action ('Scroll the page') and its result ('return a new snapshot'), using a specific verb and resource. This distinguishes it from sibling tools like navigate (which changes the URL) and click (which interacts with elements).

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 that scroll is for moving the current page's viewport, but it does not explicitly state when to use it versus alternatives such as navigate or click, nor does it provide any exclusions or alternative recommendations. It is not misleading, but it lacks clear usage guidance.

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