mouse_scroll

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

The description states the action and return value but omits important behavioral details. It does not mention that x/y causes a movement before scrolling, that instant_move and move_duration affect visible behavior, or that confirm_focus_disruption implies scrolling can disrupt focus and requires user consent. The presence of the confirm_focus_disruption parameter signals a side effect not disclosed in the description, and annotations (readOnlyHint=false) only indicate a mutation, not these nuances.

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, using two sentences and a simple Args/Returns structure. Every word earns its place, with no repetition or fluff. It front-loads the core purpose and stays focused.

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?

Although the operation seems simple, the tool has six input fields (including focus disruption and movement options) that are not described in the tool description. The description does not explain when to set x/y, how instant_move differs from move_duration, or that confirm_focus_disruption is required after explicit user consent. Given the complexity of the nested input and the presence of an output schema, the description is under-specified and would leave an agent uncertain about correct usage.

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 input schema's top-level parameter 'params' has no description, and the overall schema description coverage is 0%, so the tool description must compensate. It does explain 'amount' with direction and mentions 'optional position', but it fails to detail x, y, instant_move, move_duration, and confirm_focus_disruption. The nested schema fields have their own descriptions, but the tool description adds minimal extra meaning.

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 starts with a specific verb and resource: 'Scroll the mouse wheel vertically.' This clearly distinguishes it from sibling tools like mouse_click, mouse_move, and mouse_drag by specifying the exact action. It also clarifies direction conventions (positive up / negative down), which removes ambiguity.

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 usage (when you need to scroll vertically) but does not explicitly state when to use this tool over alternatives, nor does it mention exclusions beyond the 'vertical' qualifier. There is no comparison with sibling tools or guidance on prerequisites (e.g., focus requirements).

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