Double Tap Screen

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

The description adds no behavioral detail beyond the annotations. Annotations already indicate this is not read-only and not destructive, but the description does not disclose potential side effects, prerequisites (e.g., screen on), or response behavior. It essentially restates the tool's purpose without additional transparency.

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, efficient sentence that front-loads the core action and coordinates. There is no wasted wording, and 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?

For a simple action with three fully documented parameters and no output schema, the description is sufficient to invoke the tool correctly. It might benefit from mentioning its distinctness from sibling tap tools, but that gap is covered by usage guidelines, not contextual completeness. The core information is 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 100%, so the parameters (x, y, device) are fully described in the schema. The description merely repeats 'x,y coordinates' without adding new meaning, which meets the baseline of 3 for high schema coverage.

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 (double-tap) and the resource (screen at coordinates). It is concise and specific, but it does not explicitly differentiate from sibling tools like mobile_click_on_screen_at_coordinates or mobile_long_press_on_screen_at_coordinates; the distinction is implied by the verb 'double-tap'.

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 guidance on when to use this tool versus alternatives. It does not mention that single taps should use mobile_click_on_screen_at_coordinates, or that double-taps are for specific gestures like zoom. The description provides no context or exclusions.

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