Click Screen

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

Annotations already indicate this is not read-only, not destructive, and operates in an open world. The description adds little behavioral detail beyond the coordinate-based click itself. It does not disclose possible return behavior, coordinate system origin, or feedback after clicking, but for a simple click action the annotation coverage provides a reasonable baseline. No contradiction with annotations exists.

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 in the first sentence, and the second sentence provides a practical prerequisite tip. Every word earns its place.

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 coordinate-click tool with fully documented parameters and adequate annotations, the description covers what an agent needs: the action, the coordinate basis, and a pointer to the element-listing tool for finding coordinates. No output schema is present, but click actions typically need no elaborate return-value explanation, so this is sufficiently 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 x, y, and device are already well-defined with their own descriptions. The tool description adds only a workflow hint about using list_elements_on_screen to find coordinates, which supports parameter usage but does not add new semantic meaning to the parameters themselves. Baseline 3 is appropriate.

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: 'Click on the screen at given x,y coordinates.' It identifies the resource (screen) and the approach (coordinates), and it distinguishes from coordinate-based siblings like double-tap or long-press by naming the specific 'click' action. However, it does not explicitly contrast itself with those sibling gesture tools, so it stops short of full sibling differentiation.

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 gives clear operational context: 'If clicking on an element, use the list_elements_on_screen tool to find the coordinates.' This tells the agent how to obtain valid coordinates before invoking the tool. It does not, however, give explicit when-not-to-use guidance against alternatives like double_tap or long_press, so it lacks full exclusionary guidance.

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