is_element_visible

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

With no annotations, the description carries the full burden of explaining behavior, but it only states the check without detailing the return value (e.g., boolean), whether it waits for the element, or how 'visible' is defined. This lack of behavioral detail could mislead an agent.

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, concise sentence with no redundant words. It directly conveys the tool's function without excessive detail, making it easy to parse.

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 the tool's simplicity and the existence of an output schema (though not shown), the description covers the essential context of checking visibility. It could be more explicit about the meaning of 'visible', but the core functionality is clear.

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 sole parameter 'selector' is adequately clarified by the description as a CSS selector, adding meaning beyond the schema's type definition. The schema coverage is high, and the description reinforces the expected format.

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 specific verb 'check' and the resource 'element matched by a CSS selector', making its purpose unambiguous. It is distinct from sibling tools like click or type_text, which perform actions rather than checks.

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 implies usage for verifying visibility, but it does not explicitly state when to choose this over other assertion tools like assert_text or wait_for_element. No alternative tools are mentioned, leaving some ambiguity for an agent.

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