Tap a UI element by its visible text label when you know what the button says but not its position or index.
Tap the element whose label matches this text. Use when you know what the button says but not its index.
| Name | Required | Description | Default |
|---|---|---|---|
| text | Yes | ||
| device | 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 provided, so the description must carry the full behavioral burden. It only describes the selection mechanism and leaves out what happens on no match, multiple matches, or device targeting, as well as any side effects or failure modes.
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 short sentences with the action front-loaded. There is no filler, and each clause contributes either the operation or the usage condition.
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?
The core use case is covered and an output schema exists, so return values do not need explanation. However, the description omits device parameter semantics and any ambiguity or failure behavior, which keeps it from being fully complete.
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 clearly defines 'text' as the label to match, but the optional 'device' parameter is left as an unexplained string with an empty default, relying on schema title and convention.
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: tap an element whose label matches the provided text. The phrase 'not its index' explicitly separates it from index-based or coordinate-based sibling tap tools.
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?
It gives an explicit trigger condition: use this tool when the visible label is known but the index is not. It does not name the alternative tools explicitly, but the condition is clear enough to route an agent correctly.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.