Tap a point

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

No annotations are provided, so the description carries the burden. It discloses the coordinate space and that it taps at a point, but doesn't mention whether the tap is a discrete event, whether it waits for UI to settle, or any side effects. The description is adequate but minimal for a simple input tool.

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?

One sentence, front-loaded with the action and coordinate space, and the parenthetical adds the critical frame-of-reference detail. Zero waste.

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 two-parameter tap tool, the description covers the essential context: coordinate space and its relationship to accessibility-tree frames. It doesn't describe return values, but no output schema exists and a tap typically returns nothing meaningful. The main gap is not naming tap_normalized as the alternative for normalized coordinates.

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 coverage is 100%, so the schema already documents both parameters. The description adds the key context that coordinates are in POINTS and align with accessibility-tree frames, which is valuable beyond the schema's 'x coordinate in points'.

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 ('Tap') and resource ('at (x, y) in POINTS'), which clearly identifies the action. It distinguishes itself from the sibling tap_normalized by explicitly noting the coordinate space, though it doesn't name the sibling directly.

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 clarifies that coordinates are in POINTS and the same space as accessibility-tree frames, which is essential context for when to use this tool versus tap_normalized. It doesn't explicitly state when not to use it, but the coordinate-space clarification implies the distinction.

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