Browser Fill

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

No annotations are provided, so the description carries the full behavioral burden. It discloses the fill action and the optional Enter press, but not whether the field is cleared, whether input events fire, whether page navigation or form submission occurs, or what side effects the default session/tab behavior has.

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 two short sentences with the core action front-loaded and no redundant prose. It is appropriately terse, though the brevity also reflects the missing parameter and side-effect guidance.

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?

Even with an output schema present, the description leaves the most important parameter (ref) unexplained and gives no guidance about side effects or when to use the optional session/tab parameters. For a five-parameter tool with no annotations, this is incomplete.

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 0%, so the description must compensate for the missing parameter documentation. Only submit's behavior is explained; ref, text, tab, and session are left undefined, and 'by ref' does not clarify where an agent obtains a valid ref.

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?

States a concrete action and target: 'Fill a field by ref' distinguishes this from broader fill-form or click tools. However, it does not explicitly contrast with browser_fill_form or clarify what a 'ref' is, so sibling differentiation is only implicit.

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 only usage hint is 'Set submit=true to press Enter afterwards,' which conditions a parameter but does not explain when to prefer this tool over browser_fill_form, browser_click_text, or browser_press_key. No alternatives, exclusions, or prerequisites are mentioned.

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