fill_form

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

No annotations are provided, so the description alone must inform behavior. It discloses the core actions (filling fields and optionally clicking submit) but does not mention side effects, error handling, or whether changes are reversible. With no annotations, this is merely adequate.

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?

Two concise sentences with no wasted words. The essential information is front-loaded: the tool fills multiple fields in one call, then details the input structure, and ends with the optional submit. This is an excellent use of space.

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 moderate complexity (nested objects, 3 parameters, no output schema), the description covers the key points: how to specify fields and the optional submit button. It does not explain order of execution or what happens on errors, but for a form-filling tool this is sufficient. It could be slightly more thorough about failure 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?

Schema coverage is 100%, so the baseline is 3. The description paraphrases the schema (e.g., 'each with a ref or CSS selector and the text to type') but adds minimal extra meaning and slightly misstates that each entry must have a ref or selector, while schema only requires text. It does not compensate for any gaps.

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 in one call, which distinguishes it from single-field tools like type_text and type_and_submit. The verb 'fill' and resource 'form fields' are specific, and the batch nature is emphasized.

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 implies use when multiple fields need filling, and the existence of sibling tools like type_text for single fields provides context. However, it doesn't explicitly state when to avoid or list alternatives, missing a chance to clarify the best use case.

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