ui_click_annotated

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

The description discloses the prerequisite and the optional generation parameter for staleness warnings. Combined with the openWorldHint: false annotation, the agent understands this is a safe UI interaction without external side effects.

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 concise, with a clear summary sentence followed by two short paragraphs. No redundant or vague statements. Every sentence adds value.

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 with two parameters, and the description covers the essential process. It lacks error handling details but is sufficient for correct invocation given the annotated screenshot context.

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?

With schema coverage at 0%, the description compensates by explaining element_id as 'Element ID number from the annotated screenshot' and generation as 'Generation counter from the screenshot response (optional, warns if stale)'. This adds meaningful context beyond the schema.

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 verb 'click' and the resource 'element by its ID from ui_take_annotated_screenshot'. It distinguishes from sibling tools like ui_click and ui_click_at by specifying annotated identification.

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 explicitly instructs to call ui_take_annotated_screenshot first, and explains the purpose of the generation parameter. However, it does not contrast with alternatives such as ui_click or ui_click_at.

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