Swipe an authorized Android screen in a chosen direction to reveal off-screen content, then observe the result to verify the scroll moved as intended.
Reveal content in a direction with one central swipe, then observe to verify movement.
| Name | Required | Description | Default |
|---|---|---|---|
| serial | No | ||
| direction | Yes | ||
| duration_ms | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, yet a scroll being 'destructive' is counterintuitive and the description never explains or mitigates that. The one useful addition, 'then observe to verify movement', suggests a verification step but stops short of saying what state changes or how to recover.
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 compact sentence with the direction/action front-loaded and no filler. It is efficiently sized even though it under-delivers on content.
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?
An output schema exists so return values need not be explained, but for a tool flagged destructive with a non-idempotent hint, three undocumented parameters, and a near-duplicate sibling (phone_swipe), the description omits the routing, parameter, and safety context an agent needs to call it correctly.
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% across 3 parameters, so the description must carry the burden. It only gestures at 'direction'; the duration_ms timing control and the serial device selector are never mentioned, leaving two parameters undocumented anywhere.
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 implies a scroll/swipe action ('Reveal content in a direction with one central swipe'), but the verb is metaphorical rather than explicit and it never uses the tool's own name or distinguishes itself from the sibling phone_swipe, which performs a nearly identical gesture. An agent can infer the purpose but cannot tell why phone_scroll is preferred over phone_swipe from this text.
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 this tool versus phone_swipe, phone_tap, or phone_tap_element. The phrase 'then observe to verify movement' hints at a follow-up workflow but does not state preconditions or when this is the right choice.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.