scroll

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

Annotations declare non-read-only, non-destructive, non-idempotent and closed-world, so the safety profile is covered. The description adds the useful default of scrolling 'wherever the cursor is' when x/y are omitted, but says nothing about whether scrolling animates, blocks, or how it interacts with focused windows.

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 front-loaded sentence with the core action first and the conditional coordinate rule second; nothing is wasted. It is terse to the point of omitting useful parameter detail, but structurally sound.

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 UI action with no output schema, the description covers the essential mechanics adequately. It still leaves the meaning of direction and amount, and any interaction with the active window, to inference from the schema.

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 coverage is only 25% (only 'amount' is described), so the description must compensate, and it does explain the x/y targeting fallback. However it never mentions 'amount' (lines to scroll) or clarifies that direction accepts up/down/left/right, leaving half the semantics implicit.

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?

States a specific verb and device ('Scroll with the mouse wheel') plus the coordinate targeting rule, which is more than the bare name. It doesn't explicitly distinguish itself from siblings like drag or click, but the action is unambiguous on its own.

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?

No when-to-use guidance, no prerequisites, and no reference to alternatives such as drag (which might also move content). The only contextual hint is the cursor-position default, which describes mechanics rather than when to invoke the tool.

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