assert_element

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

With no annotations provided, the description itself must disclose behavior. It does so effectively by explaining the default timeout of 7 seconds when timeout is 0 or None, and by stating that an exception is raised if the element is not found within that timeout. This gives an agent a clear model of the tool's wait-and-fail behavior.

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 sentences with no filler. The primary purpose is stated first, followed by the timeout default and exception behavior. Every sentence contributes essential operational information.

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 assertion tool, the description covers the essential behavioral contract: presence check, timeout semantics, and failure outcome. The only notable gap is the lack of detail about selector syntax, but the parameter name and tool name make the intended value reasonably inferable.

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 0%, so the description must compensate. It adds meaningful semantics for the timeout parameter, clarifying that 0 or None triggers a 7-second default. However, it does not define or constrain the selector parameter beyond its obvious relationship to the tool's purpose, nor does it mention supported selector formats.

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 states a precise action: asserting that an element is present in the DOM. It differentiates itself from the sibling assert_element_visible by specifying DOM presence rather than visibility, and the exception behavior reinforces the assert semantics.

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 makes the core use case clear—asserting element presence with a configurable timeout. However, it does not explicitly contrast with sibling tools like wait_for_element_present or assert_element_visible, so an agent receives no guidance on when to choose this tool over those alternatives.

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