Click Screen

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

The destructiveHint annotation already flags this as potentially destructive, and the description doesn't add further behavioral details beyond the click action. It provides a useful workflow hint but not additional side-effect information, which is acceptable given the simple nature of the 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?

The description is two short sentences with the action first. No redundant phrases, every sentence serves a purpose.

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?

The tool is simple, all params are documented, and the annotation covers the destructive nature. The description gives enough context for using coordinates and when to use list_elements. Minor lack of success/failure details is acceptable without an output schema.

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%, with descriptions for x, y, and device. The description doesn't add new semantics beyond the schema, but the guidance about element coordinates complements the parameter meaning. 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 identifies the action as clicking at x,y coordinates with a specific verb and resource. It differentiates from sibling tools like double_tap or long_press by focusing on a single coordinate-based click. It also mentions an alternative for element-based clicking.

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?

It explicitly states that for clicking on an element, one should first use list_elements_on_screen to find coordinates, providing direct guidance on when to use this tool versus the alternative. It doesn't explicitly exclude other gesture tools, but the guidance is clear and actionable.

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