Hover over Element by Description

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

The description adds significant behavioral context beyond annotations: it states the hover is 'real :hover (not synthetic)' and lists triggered effects like tooltips, dropdown menus, and hover-only buttons. Annotations already indicate non-read-only, non-idempotent, and open-world, and the description enriches this without contradiction.

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 very concise with two sentences plus a usage note. No unnecessary words. The key information is front-loaded (purpose and behavioral trait).

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 has only one parameter and an output schema exists, the description provides complete context: what the tool does, when to use it, behavioral details, and alternatives for edge cases. No missing critical information.

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 only parameter `description` has no schema description (0% coverage) and the tool description does not explain what format the description should take (e.g., CSS selector, text, or other). While the tool's purpose is clear, the semantics of the parameter are under-specified.

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 'Hover the mouse over the element best matching `description`.' It specifies the verb 'hover' and the resource 'element by description'. Among siblings like click_what and type_into, it distinguishes itself by the hover action.

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 says 'Use after the element shows up in observe' and provides alternatives: 'introspect via inspect_element or fall back to eval_js' for elements observe filters out. This gives clear when-to-use and when-not-to-use guidance.

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