input_roll

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

With no annotations available, the description must carry the behavioral disclosure burden, but it only states that the tool simulates a rolling gesture and requires distances. It does not mention practical behavioral details such as units, sign conventions, whether this is a trackball-style roll, or whether the gesture has side effects on the device, leaving notable transparency gaps.

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 main description is one focused sentence that leads with the action and parameter semantics, earning its place. The phrase 'Requires dx and dy parameters' is somewhat redundant with the schema's required fields, but the description is still appropriately sized and easy to scan.

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 two-parameter tool with no output schema, the description covers the essential action and parameter meanings, so it is minimally viable. It lacks broader context such as error conditions, whether the gesture triggers scrolling, or relationship to input_swipe, making it only partially 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 description coverage is 0%, so the description's phrase that dx and dy are 'rolling distances in the x and y directions' adds real meaning beyond the bare schema fields. However, it omits useful specifics like units, allowed ranges, sign meaning, or how the values map to on-screen movement, so it only partially compensates for the lack of schema descriptions.

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 states a specific action ('simulates a rolling gesture') and a target ('connected Android device'), making the tool's purpose clear. It does not explicitly contrast itself with sibling tools such as input_swipe, so it misses the full differentiation step, but the verb and resource are identifiable enough to understand its function.

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 when the tool is used: when a rolling gesture with dx/dy is needed, but it provides no explicit guidance about when to choose input_roll over the many related sibling tools such as input_swipe or input_tap. It offers no exclusions or alternative conditions, so an agent still has to infer the right context.

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