browser_fill_form

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

Annotations declare destructiveHint: true and openWorldHint: true, but the description adds no behavioral details beyond that. It does not disclose that filling may trigger events or overwrite existing values, leaving the agent with minimal understanding of side effects.

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 very concise (4 words), but it is not structured to convey important details. While brevity is valued, the description lacks necessary context and does not earn its place as a standalone guide.

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 an output schema and the complexity of the nested input, the description is insufficient. It does not explain return values, error conditions, or how to use the tool effectively, leaving significant gaps.

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 has 100% coverage with property descriptions for 'target', 'name', 'type', and 'value'. The tool description does not add any additional meaning beyond the schema, such as interaction between multiple fields or order of operations. Baseline score of 3 is appropriate.

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 verb (fill) and resource (form fields), but it does not differentiate from sibling tools like browser_type, which fills a single field. The purpose is understandable but could be more explicit.

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 this tool versus alternatives, such as browser_type for single fields. No context about prerequisites or typical usage scenarios is given.

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