screen_tap

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

With no annotations provided, the description carries full burden, but it only mentions 'validated' without explaining the validation process, failure behavior, or side effects of tapping. It does not disclose whether this is a system-level tap, requires permissions, or what happens if coordinates are invalid.

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 no redundancy. It conveys the core action efficiently, though it errs on the side of being too terse.

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 4 parameters, no annotations, and no output schema, the description is insufficient. It omits key behavioral details, parameter semantics, and fallback context, making it inadequate for reliable tool selection and invocation.

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 should compensate, but it only uses the term 'device-pixel coordinates,' which is already encoded in the coordinate_space const. The purpose of x, y, and especially verify_change remain unexplained.

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 identifies the action ('Tap') and the target ('validated native device-pixel coordinates'), and the phrase 'as a fallback' hints at being an alternative to other methods like ui_tap. However, it does not explicitly name the primary tool it falls back from, so differentiation is implicit.

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 phrase 'as a fallback' implies this tool should be used when other tapping methods (e.g., ui_tap) are unavailable, but it provides no explicit when/when-not guidance or named alternatives. The usage context is only implied, not fully spelled out.

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