Fill form

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

Mentions 'one settle for the whole form', implying it waits for the page to settle after filling. It does not describe side effects such as validation, auto-submit, or error behavior, and the annotations provide little additional clarity.

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 extremely concise, using only two short sentences with no filler or redundant 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?

The description is enough to distinguish this from single-field tools like browser_type and select_option, and it conveys the main batching benefit. It lacks details about selector syntax and supported input types, but remains usable for typical form-filling scenarios.

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 settle parameter is clearly described. The fields parameter describes the expected shape as {target, value} or {target, values} for multi-selects, but does not clarify what target refers to or the value types, leaving some ambiguity.

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?

Clearly states the action (fill form fields) and the scope (many fields in one call), with an explicit benefit. The term 'target' in the fields parameter is not defined, but the overall purpose is unambiguous.

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?

Positions the tool as the fastest way to complete a form and mentions one round-trip and one settle, giving agents a strong signal to use it for multi-field forms. It does not explicitly contrast with browser_type or select_option, but the sibling tool list makes the alternatives apparent.

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