Simulate a drag gesture on a connected Android device from one coordinate to another; increase duration_ms for slower drags.
Swipe/drag from (x1,y1) to (x2,y2). Increase duration_ms for slow drags.
| Name | Required | Description | Default |
|---|---|---|---|
| x1 | Yes | ||
| x2 | Yes | ||
| y1 | Yes | ||
| y2 | Yes | ||
| device | No | Device serial from list_devices (omit when exactly one device is connected). | |
| duration_ms | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It discloses only that duration_ms governs drag speed; it omits that this injects real touch input on a device (which can trigger destructive UI actions), whether it is cancellable, how the target device is chosen, and what is returned.
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 tight sentences with zero padding and the core gesture semantics front-loaded ahead of the tuning detail. It is very short relative to a 6-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 6-param device-gesture tool with no annotations, no output schema and 17% schema coverage, the description is under-specified. An agent gets no guidance on device targeting, return behavior, or disambiguation from 'scroll' and 'tap'.
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 17% (only 'device' is documented), so the description must compensate. It does map x1,y1→x2,y2 as start/end points and adds real meaning to duration_ms ('increase for slow drags'), but leaves the device parameter and duration_ms units/default 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?
States a specific verb+resource ('Swipe/drag') with the coordinate endpoints, which is concrete and unambiguous. However, it does not differentiate from the sibling 'scroll', which is a closely overlapping gesture tool an agent would plausibly confuse it with.
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?
Only guidance offered is 'Increase duration_ms for slow drags', which is a tuning hint rather than a when-to-use rule. It never says when to prefer swipe over scroll or tap, nor when the optional device parameter must be supplied, leaving selection to inference.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.