tap

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden of behavioral disclosure. It states the tap action and the coordinate-or-selector constraint, but does not explain what happens if a selector matches multiple elements, whether coordinates and selectors can be combined, timeout behavior, or failure outcomes.

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 two short sentences with no filler. The core action is front-loaded, and the second sentence adds an essential usage constraint without redundancy.

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?

Given 9 parameters, 0% schema description coverage, and no annotations, the description is too sparse. An agent cannot reliably determine which selector parameters to fill, how they combine, or what precedence applies when both coordinates and selectors are provided.

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%, and the description barely compensates. It identifies x/y as coordinates and implies selector-based lookup, but does not enumerate which of the many fields (text, index, xpath, resource_id, text_contains) count as selector fields, nor does it explain timeout or description parameters.

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 a specific verb ('tap') and resource (screen or element found by selector), and distinguishes coordinate-based taps from selector-based taps. It differentiates well from siblings like double_tap and long_press by describing a single tap action on the screen.

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 does not explain when to use this tool instead of alternatives such as double_tap, long_press, or swipe. It offers invocation guidance about coordinates versus selectors, but no contextual routing between sibling tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.