browser_fill_form

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

The description adds no behavioral context beyond the annotations. Annotations already indicate destructiveHint=true and readOnlyHint=false, but the description does not explain that filling fields may permanently change the page state. No mention of how different field types are handled (though the schema partially covers this).

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?

At just four words, the description is extremely concise and to the point. No fluff or redundancy. However, it could be slightly more informative without losing conciseness.

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?

The description is too minimal for a tool that modifies a page. It lacks context about prerequisites (e.g., requiring a page snapshot), the relation to sibling tools like browser_click or browser_type, and what 'fill' entails for various control types beyond what the schema already says. The destructive hint is present but not elaborated.

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% for the 'fields' parameter, detailing each subfield. The tool description adds no extra meaning beyond the parameter name and the fact it fills multiple fields. Baseline 3 is appropriate since the schema does the heavy lifting.

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 states the action (fill) and the resource (form fields), and the word 'multiple' distinguishes it from single-field tools like browser_type. However, it does not explicitly differentiate from browser_select_option for combobox fields.

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 on when to use this tool versus alternatives (e.g., browser_type for single fields, browser_select_option for dropdowns). No mention of prerequisites like having a page snapshot or that the form fields must exist.

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