browser_fill_form

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

Annotations already indicate destructiveHint=true and readOnlyHint=false, but the description adds no further behavioral context (e.g., that fields must match snapshot elements, that filling checkboxes uses true/false, or that the tool may fail if elements are stale). No contradictions with annotations.

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 only four words, the description is under-specified. While front-loaded, it does not earn its place—it fails to convey essential context about the nested parameters or behavior, sacrificing utility for brevity.

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 (nested array of field objects with multiple types) and no output schema, the description is inadequate. It does not explain how fields should be structured, what happens on error, or how it interacts with a page snapshot. Sibling tools with similar scope (e.g., browser_type) would benefit from more 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?

Schema coverage is 100% (all properties described), so the baseline is 3. The description adds no additional meaning beyond what the schema provides (e.g., no typical usage patterns or format examples).

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 tool's action (fill) and resource (form fields). It is specific enough to distinguish from sibling tools like browser_type (single field) or browser_select_option, though it could explicitly contrast with these for full differentiation.

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 or browser_select_option. It does not mention prerequisites (e.g., a snapshot required), nor does it explain when not to use it.

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