browser_fill_form

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

There are no annotations, so the description must convey behavioral traits. It only states 'Fill multiple form fields' with no mention of event triggering, value overwriting, hidden fields, or return behavior. The tool modifies form state, but the description does not disclose potential side effects or permissions needed.

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 short phrase with no filler, earning a high score for brevity. However, it is under-specified, which slightly reduces its effectiveness.

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 lack of annotations and output schema, the description is too sparse. It does not explain how to construct the 'fields' array, what each field entry requires, or what the tool returns. This leaves significant gaps for an agent.

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 already describes both parameters (sessionId and fields) at 100% coverage. The description adds no extra meaning beyond that, leaving the structure of each item in the 'fields' array undefined.

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 multiple form fields' clearly identifies the verb (fill) and resource (form fields), distinguishing it from sibling tools like browser_type or browser_click which handle single fields. However, it lacks specificity about the mechanism or scope beyond 'multiple'.

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 for when to use this tool over alternatives. Sibling tools such as browser_type and browser_select_option exist, but the description does not explain when bulk filling is preferred or any prerequisites like focusing on the form.

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