fill_form

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

The description adds value beyond annotations by specifying that events are 'React-compatible', indicating synthetic event dispatch. It also lists handled element types. Annotations already denote idempotency (idempotentHint=true) and non-destructive nature (destructiveHint=false). No contradiction.

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 extremely concise: two sentences totaling ~15 words. It front-loads the verb 'fill' and quickly covers scope. No superfluous information.

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 (5 parameters, batch operation) and lack of output schema, the description omits details about return values, error handling for missing fields, or effect of submit_selector. It's minimally adequate but not fully comprehensive.

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%. The description does not elaborate on individual parameters beyond what the schema already provides. The mention of 'React-compatible events' is general context, not parameter-specific, so the description adds minimal meaning beyond the schema.

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 purpose: batch filling form fields with React-compatible events. It specifies the supported element types (input, select, checkbox, radio, textarea), distinguishing it from siblings like type_text for single-field input.

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 provides no guidance on when to use fill_form versus alternatives like type_text or click. It does not mention efficiency trade-offs or appropriateness for single-field vs. multi-field scenarios.

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