fill

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

No annotations are provided, so the description carries full burden. 'Fill an input field' implies a mutation (changing input value), but it doesn't disclose behavioral traits like whether it triggers events, requires the field to be interactable, handles errors if the selector is invalid, or has side effects. This is a significant gap for a mutation tool with zero annotation coverage.

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 'Fill an input field' is extremely concise with zero waste—it's a single, front-loaded sentence that directly states the action. Every word earns its place, making it efficient for quick understanding.

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 (a mutation operation with 2 parameters), lack of annotations, and no output schema, the description is incomplete. It doesn't explain return values, error handling, or interaction details, leaving gaps that could hinder an AI agent's ability to use it correctly in a web automation context.

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 100%, so the schema already documents both parameters ('selector' and 'value') with clear descriptions. The description adds no meaning beyond this, such as examples of CSS selectors or validation rules for the value. Baseline 3 is appropriate when the schema does the heavy lifting.

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 'Fill an input field' states a clear verb ('fill') and resource ('input field'), but it's vague about scope and doesn't differentiate from sibling tools like 'select' or 'get_selected_element' which might also interact with input fields. It provides basic purpose but lacks specificity about what type of input fields or context.

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 offers no guidance on when to use this tool versus alternatives. With siblings like 'select' (which might select options) or 'get_selected_element' (which might retrieve input values), there's no indication of when 'fill' is appropriate, such as for text inputs versus other form elements, or prerequisites like needing an element to be visible.

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