assert_clickable

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

With no annotations provided, the description carries the behavioral disclosure burden. It clearly states that no click occurs, that it hit-tests, and that it reports an intercepting element when something covers the target. This is meaningful non-obvious behavior beyond the tool name.

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?

Two sentences, front-loaded with the key distinction, and every sentence adds value. There is no filler or repetition of the tool name.

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 and the description covers purpose and core behavior, but it is incomplete for correct invocation because an agent cannot tell how to populate ref or selector. With no output schema, the description also does not fully describe the result shape beyond 'reports the element that would intercept'.

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?

The schema has two parameters, ref and selector, with 0% schema description coverage, and the description adds no information about either. It never explains ref vs selector, whether they are alternatives, required, or how they locate the element. The description does not compensate for the empty schema at all.

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 uses a precise verb-resource combination: 'Hit-test an element WITHOUT clicking' and clarifies the intent by asking 'would a real click actually land on it?' This distinguishes the tool from siblings like click, click_text, and click_role while also differentiating it from visibility assertions by focusing on hit-testing rather than visibility.

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 provides clear usage context: use it to answer 'why did my click do nothing?' before spending a real click. This implies the right moment to invoke it and contrasts it with click tools, though it does not explicitly name alternative tools or state when not to use it.

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