fill

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

With no annotations, the description carries full burden. It discloses that it fires input/change events, which is good. However, it does not specify behavior on hidden elements, error handling, or whether it scrolls to the element. The disclosure is adequate but not comprehensive.

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 two sentences, front-loading the primary action and adding a necessary capability requirement. No unnecessary words.

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?

For a simple form-fill tool with only two parameters and no output schema, the description is largely complete. It could mention what happens if the selector matches no element or multiple elements, but given the tool's simplicity, the current level is nearly sufficient.

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?

Although schema coverage is 100% with basic descriptions, the tool description adds significant meaning by specifying the valid element types (input, textarea, etc.) and the event-firing behavior. This clarifies the purpose of the 'value' parameter beyond 'Value to set'.

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 action ('Set the value'), the target element types ('input, textarea, select, or contenteditable'), and the side effect ('fire input/change events'). This distinguishes it from sibling tools like 'click' or 'query_dom'.

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 mentions a prerequisite ('Requires the 'interact' capability') but provides no guidance on when to use this tool versus alternatives, or when not to use it. There is no explicit context about use cases or exclusions.

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