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

No annotations are provided, so the description carries the full disclosure burden. It reveals only that ref triggers a scroll-into-view, omitting direction/defaults, what happens when amount and deltaY are both supplied, conflict/priority rules, and whether the call returns anything or requires focus. For a mutation-style interaction tool with zero annotation coverage, this is a substantial gap.

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 short sentence with the core action front-loaded and the optional-ref nuance second; no wasted words. The terseness is a deliberate trade-off rather than padding, though it leaves gaps handled elsewhere in the scoring.

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, 17% schema coverage, no annotations, and no output schema, this tool needs considerably more context than one sentence provides. An agent cannot determine how to set amount versus deltaX/deltaY or what result to expect after calling.

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 description coverage is only 17%, so the description must compensate and it largely does not: only ref gets any explanation ('scrolls element into view first'). amount, deltaX, deltaY, tab_id, and their interaction (e.g., vertical vs horizontal scrolling, units, defaults) are left completely undocumented in both schema and description.

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 states a specific verb and mechanism ('Scroll wheel') plus a secondary behavior ('optional ref scrolls element into view first'), so an agent knows exactly what the tool performs. It does not explicitly contrast itself with siblings like browser_press_key or browser_snapshot, but the scroll-wheel framing is distinctive enough to disambiguate.

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 on when to reach for this tool rather than alternatives (keyboard paging, snapshot, drag), and no prerequisites or exclusions. The only usage hint is implicit in the words 'scroll wheel'.

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