browser_fill_form

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

Annotations already indicate this is not read-only and is destructive (readOnlyHint=false, destructiveHint=true). The description adds no additional behavioral context, but it is consistent with the annotations. No contradictions, but also no extra value beyond the annotation safety profile.

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, concise sentence with zero filler words. It communicates the core action effectively and is immediately understandable.

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?

This tool has a complex nested schema and is part of a large sibling set, but the description gives no context about behavior beyond 'fill fields'. No output schema exists, and important details like whether existing values are cleared, whether the form is submitted, or how to target elements are absent. The schema covers parameters, but the description lacks operational context.

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 schema provides 100% coverage with descriptions for all fields, including target, name, type, and value. The description itself adds no additional parameter information, so it earns the baseline score of 3.

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 uses a clear verb ('Fill') and specifies the resource ('multiple form fields'), which states the tool's function. However, it does not differentiate from sibling tools like browser_type or browser_select_option, which also interact with form 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 is provided on when to use this tool versus alternatives. The description only states what it does, not when to prefer it over browser_type for a single field or browser_select_option for dropdowns. There are no exclusions or explicit use cases.

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