browser_fill

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

With no annotations, the description carries the full burden. It discloses the key behavior of clearing the field before filling ('Clear and fill'), which is useful. However, it does not mention potential side effects like event triggering, visibility requirements, or return values, leaving gaps.

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, front-loaded sentence with no redundant content. Every word adds meaning, making it highly efficient and easy to parse.

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?

The tool is relatively simple, and the description covers its core function. However, without any output schema or mention of return behavior, and given the many sibling tools, the lack of guidance on how this differs from browser_type makes the description incomplete for choosing the right tool in all contexts.

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% documentation coverage for all parameters, including 'value' (empty string clears), 'selector' (selector/ref), and 'sessionId'. The description adds no additional parameter information beyond what the schema already states, so the baseline of 3 applies.

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 'Clear and fill a text input field with the specified value' uses a specific verb ('fill') and a clear resource ('text input field'), and explicitly mentions the clearing behavior. This distinguishes it from sibling tools like browser_click or browser_type by indicating a direct value-setting action.

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. With siblings like browser_type (likely simulating keystrokes), the absence of any mention of when to prefer 'fill' over 'type' leaves the agent without clear selection criteria.

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