Scroll

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

The description discloses a critical behavioral constraint: 'Requires admin mode AND MACCTL_ALLOW_INPUT=true.' This is beyond what annotations provide (which only indicate non-readonly, non-destructive). It also clarifies that scrolling applies to whatever is under the cursor/frontmost, adding operational 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?

A single sentence that front-loads the action and target, followed by the permission requirement. Zero wasted words; every element earns its place.

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 input-action tool with full schema coverage, the description covers the core behavior and the only notable prerequisite (admin mode). It does not describe return values, but as a side-effect action, that is not critical. It is complete enough for correct invocation.

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 100%: both 'direction' and 'amount' are fully described in the input schema. The description adds no extra parameter semantics beyond what the schema already states, so the baseline of 3 applies.

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: 'Scroll the mouse wheel in a direction by a number of lines' with a specific target ('over whatever is under the cursor / frontmost'). This distinguishes it from sibling input tools like click, move_mouse, or key_press.

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?

It provides context about the target (cursor/frontmost) but does not explicitly guide when to use this tool over alternatives like move_mouse or key_press. No exclusionary language or mention of alternatives. However, the action is distinct enough that the intended use is fairly obvious.

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