fill

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

With only readOnlyHint=false as annotation, the description carries the burden for behavioral disclosure, but it only states what is filled, not how. It does not mention side effects like clearing existing values, triggering events, or behavior on unsupported elements. No detail on selecting options from a <select> is given.

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 sentence that is direct and without wasted words. It efficiently captures the core purpose.

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?

While the tool is simple and parameters are well-documented in the schema, the description lacks sufficient context for an agent to decide when to use this instead of sibling tools like type_text or fill_form. It also does not mention the role of the snapshot uid or the includeSnapshot parameter, which are relevant for practical usage.

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 covers all parameters with descriptions (uid, value, includeSnapshot), so the tool description adds no additional semantic value. Baseline 3 applies because schema coverage is 100%.

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's function with specific verbs and targets: 'Type text into an input, text area or select an option from a <select> element.' It distinguishes from siblings like click or hover by specifying form-filling behaviors, including the unique ability to select from a <select> element.

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 such as type_text or fill_form. The description does not mention exclusions, prerequisites, or scenarios where another sibling would be more appropriate.

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