Capture the current emulator screen and optionally retrieve the accessible UI tree to inspect the visible app state and debug layout.
Return current emulator PNG and optional accessible UI tree.
| Name | Required | Description | Default |
|---|---|---|---|
| include_ui_tree | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds no behavioral context beyond the annotated facts, such as whether the screenshot is freshly captured, the cost of including the UI tree, or any session requirements. It does not contradict the annotations.
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, front-loaded sentence that names the primary output and the optional addition. Every word earns its place; there is no filler or repetition of schema details.
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 read-only inspection tool, the description covers the return artifacts: the PNG and optional UI tree. No output schema exists, but the description states enough about the result. It could add a bit more about what 'accessible UI tree' contains or when include_ui_tree matters, but the core context is present.
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%, so the description must compensate. It does this by clarifying that the single parameter controls whether the accessible UI tree is included, and the word 'optional' conveys the boolean toggle semantics. This is meaningful guidance for a one-parameter boolean tool.
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 exactly what the tool does: it returns the current emulator PNG and, optionally, an accessible UI tree. The verb 'Return' and the specific resources make its purpose immediately clear and distinguish it from sibling tools like apk_preview_interact or apk_preview_configure_display.
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 gives no guidance about when to use this tool versus the sibling apk_preview_* tools. There are no explicit conditions, alternatives, or exclusion criteria, so an agent must infer usage from the tool name and the bare description.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.