Taps a UI element by handle or device coordinates on an Android emulator or device, then waits for the screen to settle and returns the refreshed element list.
Tap an element handle ("e7") or device coordinates ("540,1200").
| Name | Required | Description | Default |
|---|---|---|---|
| target | Yes | ||
| max_wait_ms | No | ||
| observe_after | No |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are supplied, so the description carries the full burden for an action that mutates UI state, yet it discloses nothing about blocking behavior, what max_wait_ms bounds, or what observe_after=true actually does after the tap. The default observe_after=true is a meaningful behavioral trait (it presumably captures a post-tap state observation) that the description leaves entirely unexplained.
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 tight sentence with the two accepted input forms front-loaded and no filler. It is well-formed but so terse that the terseness trades away needed detail rather than achieving efficiency.
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?
An output schema exists, so return values needn't be described, and the target formats are covered. However, for a state-changing interaction tool with zero annotations, silence on timing/waiting and the observe-after behavior leaves the agent guessing about side effects and post-call state.
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 clarifies only the required target parameter's accepted formats and says nothing about max_wait_ms (units, what it waits for) or observe_after (what gets observed and returned). Two of three parameters remain semantically opaque.
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 gives a concrete verb ("tap") and states the two accepted target forms with literal examples ("e7" for an element handle, "540,1200" for coordinates). That is enough to distinguish it from sibling tap_text, which presumably taps by visible text rather than handle or coordinates, though the distinction is only implied.
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 explicit guidance on when to use tap versus tap_text, long_press, or swipe, and no prerequisites or failure conditions are stated. The target format examples hint at usage but do not constitute when-to-use guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.