scroll

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

Annotations already declare readOnlyHint=false, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds genuinely new behavioral detail — that dy>0 means downward and the unit is grid cells — but says nothing about whether scrolling targets the page or a specific element, whether it is animated or how far a unit actually travels.

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 short sentences with the core meaning front-loaded and no filler. The terseness borders on under-specification for a five-parameter tool, but nothing written is wasted.

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 tool with five parameters, zero required fields, low schema coverage and no output schema, the description is far too thin. An agent still cannot tell whether x/y target an element or the viewport, what dx does, what the defaults are, or what the call returns.

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 20% (only id is documented, as an alternative to x/y), so the description must carry the load. It clarifies dy's sign and unit but leaves x, y, dx, their defaults, and whether the unit applies to dx as well completely unexplained.

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?

"滚轮" (scroll wheel) names a specific action, and the dy direction convention makes the intent unambiguous versus siblings like click, move, drag or key. It stops short of stating what is being scrolled (page vs. element under the cursor), so it is clear but not fully differentiated.

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 use scroll versus observe/screenshot/find, nor any prerequisite such as needing a prior observe for the id parameter. The only usable hint is the sign convention for dy, which is direction semantics rather than when-to-use guidance.

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