tap_screen

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

With no annotations provided, the description must carry the full burden of behavioral disclosure. It only states the action without mentioning side effects, device requirements, coordinate system origin, or multi-device handling (e.g., serial parameter). The behavior is not misleading but is severely under-explained for an agent needing to understand implications of the tap.

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 with zero wasted words. It efficiently states the core purpose, and there is no extraneous information. It is appropriately sized for the tool's simplicity.

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 the tool's simplicity, a one-sentence description might be minimally adequate, but it lacks context about device selection, coordinate origin, and when to use it. The schema covers parameter details, but the description does not provide enough surrounding context for an agent to confidently invoke it in varied situations. It feels complete for a trivial tap but not robustly.

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%, so the baseline is 3. The description itself adds no additional meaning beyond the schema: it doesn't clarify coordinate units (though schema lists 'pixels') or the optionality of serial. The schema already documents parameters adequately, so this is a pass-through score.

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 action ('Tap') and the resource ('the screen') with specific coordinate parameters, which distinguishes it from sibling tools like swipe_screen or send_keyevent. It is a specific verb+resource pair that unambiguously conveys the tool's function.

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 provides no guidance on when to use this tool versus alternatives such as swipe_screen or send_keyevent. There is no mention of contexts like interacting with UI elements, automating taps, or needing a connected device. No exclusions or alternative indications are given.

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