Scroll

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

The description discloses that the cursor may be moved first, that deltaY direction follows system convention, and that Accessibility permission is required. These details go beyond the annotations, which only indicate non-read-only and non-destructive, adding valuable behavioral 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?

Three short, focused sentences cover the core behavior, the cursor side-effect, the direction convention, and the permission requirement. No wasted words; the structure is efficient 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 5-parameter input tool with no output schema, the description provides the essential behavioral context: what it does, the optional cursor movement, the deltaY direction convention, and the permission requirement. Parameter details are already in the schema, making this sufficiently 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 descriptions cover all parameters, so the baseline is 3. The description adds meaningful semantic context for deltaY (positive scrolls up/content-down) and clarifies x/y as optional cursor positions, which goes beyond the schema's basic 'Move the cursor here' and 'Vertical scroll amount'.

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 posts a scroll-wheel event, with optional cursor movement first. The verb 'scroll' and the specific parameters distinguish it from sibling input tools like input_click, input_drag, and input_type.

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 use when a scroll-wheel event is needed and mentions the system convention for deltaY, but it does not explicitly compare to alternatives or state when not to use it. With multiple input tools available, some exclusion guidance would help.

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