Simulate a touch gesture between two screen coordinates, with optional duration, to test mobile UI interactions.
Swipe from one point to another on the screen
| Name | Required | Description | Default |
|---|---|---|---|
| x1 | Yes | Start X coordinate | |
| x2 | Yes | End X coordinate | |
| y1 | Yes | Start Y coordinate | |
| y2 | Yes | End Y coordinate | |
| device_id | No | Target device ID. If omitted, uses the default device. | |
| duration_ms | No | Duration of the swipe in milliseconds (default: 300) |
Changes observed during successful MCP inspections.
v3.8.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry the full burden of behavioral disclosure. The description only says 'swipe from one point to another' and fails to disclose that this is a user-like gesture that may trigger animations, scroll actions, or require screen stability. It does not explain potential side effects or prerequisites (e.g., device must be unlocked). This is a significant gap for a UI interaction tool.
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 description is a single sentence, which is efficient and front-loaded with the core action. It is not verbose, but it is also under-specified, which is why it scores 4 rather than 5. Every word earns its place, but there is no extra context to help the agent.
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?
The tool has 6 parameters, no output schema, and no annotations, yet the description is extremely brief. Critical missing context includes coordinate system specifics, duration meaning, device targeting, and potential side effects. For a gesture tool, the description is incomplete for an agent to invoke it correctly without additional knowledge.
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 100%, so the schema describes each parameter's meaning (e.g., x1 is start X coordinate). However, the description adds no additional semantics, such as coordinate system origin (e.g., pixels from top-left), how duration affects behavior, or that device_id can target a specific device. Baseline 3 is appropriate since the schema covers the basics, but the description does not compensate for missing context like coordinate origin.
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 (swipe) and the resource (screen), but it is generic and does not distinguish from sibling tools like scroll_down or scroll_up, which are specific types of swipes. An agent might confuse 'swipe' with scroll gestures without additional context.
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 provides no guidance on when to use this tool versus alternatives such as scroll_down, scroll_up, or tap_xy. There is no mention of use cases like swiping for navigation, dismissing elements, or scrolling through lists. The agent is left to infer when this tool is appropriate.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.