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

Annotations already declare destructiveHint=true, openWorldHint=true and non-idempotency, and the description adds genuinely new behavior: it is non-atomic (stops at the first failing field) and reports which fields were filled, and it never submits. It does not explain why the operation is destructive (existing values being overwritten), which is the one relevant gap.

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?

Four short sentences, front-loaded with the core action and value-type contract, followed by the important negative constraint (does not submit) and the return behavior. No redundant restatement of the schema or title.

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?

With no output schema, the description correctly covers the return value ('the elements and text in view, with the same numbers'), which is exactly what an agent needs to chain a following step. Failure semantics and submission behavior are covered; only the destructive/overwrite consequence of filling fields is unstated.

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%, so the baseline is 3, but the description adds real meaning by mapping value types to widget kinds (text for text fields, option label for drop-downs, true/false for checkboxes, radios and switches) and by stating fields are processed 'in the order a person fills them'. The app and dialog parameters are left to their own schema descriptions.

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 first sentence gives a specific verb and resource ('Fills several fields in one step') and immediately differentiates itself from single-element siblings like cotlet_browser_type or cotlet_browser_select by emphasizing batching. It also enumerates which widget kinds are supported and what value type each expects.

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?

It states a clear follow-up condition ('Does not send the form: click its button after'), which tells the agent how this tool relates to a click step. It does not explicitly say when to prefer this over repeated cotlet_browser_type/cotlet_browser_select calls, but the 'several fields in one step' framing makes the choice obvious.

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