mobile_get_screen_sizeRetrieve the screen dimensions of a mobile device in pixels by specifying its device identifier. Use this to determine available screen space for UI automation and testing.
Get the screen size of the mobile device in pixels
| Name | Required | Description | Default |
|---|---|---|---|
| device | Yes | The device identifier to use. Use mobile_list_available_devices to find which devices are available to you. |
Changes observed during successful MCP inspections.
v0.0.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, so the description need not restate safety. It adds the unit 'pixels', which is useful context, but does not disclose other traits like return format or potential side effects. With annotations covering safety, a 3 is appropriate for this simple read-only operation.
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 sentence with zero filler, front-loaded with the core purpose. Every word adds value and the unit specification is efficient.
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 one-parameter, read-only getter with full schema coverage and annotations, the description is nearly complete. It lacks explicit mention of the return structure (e.g., width and height), but 'screen size in pixels' reasonably implies dimensions, making it adequate for an agent to call 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 100%: the 'device' parameter is fully described in the schema, including a pointer to mobile_list_available_devices. The tool description adds no parameter-specific information beyond the schema, so baseline 3 is warranted.
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 verb 'Get' and the resource 'screen size of the mobile device' with the unit 'pixels'. It is specific and distinguishable from all sibling tools, none of which address screen size.
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 is straightforward and implies when to use it (whenever the screen size is needed). While it does not explicitly name alternatives, no sibling tool competes for the same purpose, so the usage context is clear without exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.