Launches a URL on a connected Android device using its default browser or matching app; specify the device serial when multiple devices are connected.
Open a URL in the device's default browser or matching app.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | ||
| device | No | Device serial from list_devices (omit when exactly one device is connected). |
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 behavioral burden. It discloses only that a URL opens in a browser or app, saying nothing about side effects, return values, device connection requirements, or error handling.
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, front-loaded sentence with no filler or redundancy. It is appropriately sized for the tool's simplicity.
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 device action with no output schema and one schema-documented parameter, the description is minimally adequate. However, with no annotations, it omits key context such as the need for a connected device and what the action returns.
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 only 50%: the 'device' parameter is documented in the schema, but 'url' is a bare string with no description. The description does not clarify URL format, scheme handling, or device selection, so it fails to compensate for the coverage gap.
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 verb and resource ('Open a URL') plus the mechanism ('default browser or matching app'). It implicitly distinguishes from launch_app, which launches packages, but never names or contrasts any sibling explicitly.
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 launch_app, shell, or tap. The purpose implies a use case, but prerequisites and alternatives are left unstated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.