app_scroll

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

With no annotations provided, the description carries the full burden. It discloses key behaviors (positive/negative delta directions, viewport vs. element scrolling). However, it does not mention error handling, delta limits, or whether the scroll is instant or animated. Adequate but minimal extra context.

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?

Two sentences, no fluff. The first sentence states the core action, the second clarifies direction and selector usage. Perfectly sized and 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?

For a simple scrolling action with no output schema and 0 required parameters, the description covers the essential usage (delta directions, selector). It could mention what happens on error or if selector is invalid, but given the low complexity, it is fairly complete.

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 100%—all three parameters (deltaX, deltaY, selector) are described in the schema. The description adds a bit of context (e.g., 'Positive deltaY scrolls down') but mostly reiterates the schema. Baseline 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 action (mouse-wheel scroll), the resource (pixel delta), and distinguishes from sibling tools like app_drag or app_click. It specifies deltaY and deltaX directions and mentions viewport vs. a specific scrollable pane via selector.

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 the tool (scrolling with a mouse wheel) and mentions the selector for specific panes, but does not explicitly state when not to use or compare to alternatives like app_drag (which could also scroll some elements). No explicit exclusions or conditions.

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