browser_fill_form

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

The description gives minimal behavioral insight beyond 'fill form fields'. It does not disclose whether existing fields are cleared, if the form is submitted, or any side effects. With no annotations, the description fails to convey safety or operation details.

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 that gets straight to the point without any fluff. It is properly front-loaded and 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 complexity (3 parameters, needs a browser session), the description fails to mention required context like session existence, form state, or output behavior. An output schema exists but is not utilized in the description.

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 input schema already provides full descriptions for all three parameters (100% coverage), including an example for form_data. The description adds no additional semantic value beyond what the schema offers.

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 tool fills multiple form fields at once, distinguishing it from single-field tools like browser_type. However, it does not specify the use of CSS selectors or the ability to handle various selector types, which is covered in the schema but could be highlighted.

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?

No guidance is provided on when to use this tool versus alternatives like browser_type or browser_click. The description does not mention prerequisites (e.g., form must be loaded) or 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.