browser_fill

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

No annotations are provided, so the description must carry the full behavioral burden. 'Clear and fill input' implies mutating the page, but it does not disclose side effects, whether the input must be visible or focused, how the session parameter affects behavior, or what the return value is. For a mutation tool with zero annotation coverage, this is a significant 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?

The description is extremely concise at one phrase, which is technically efficient, but it is under-specified. It lacks structure and depth, providing only the bare action without any elaboration. This is brevity bordering on vagueness rather than effective conciseness.

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?

For a browser automation tool with 3 parameters, no output schema, and no annotations, the description is insufficient. It does not explain the return value, error conditions, or any behavioral nuances. An agent would lack critical information needed to call this tool correctly and understand its effects.

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 100%, with each parameter described (text, session, selector). The description adds no additional meaning beyond the schema; it merely states the tool's action. Baseline 3 is appropriate because the schema already documents parameters, but the description does not clarify how the parameters interact or any special syntax.

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 input' provides a clear verb and resource – it specifies that it clears and fills an input element. It is distinct enough from siblings like browser_click or browser_scroll, but it does not explicitly differentiate itself from similar input-related tools such as browser_set or browser_type, so it lacks full sibling 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?

There is no guidance on when to use this tool versus alternatives like browser_set, browser_type, or browser_press. No context, prerequisites, or exclusions are provided, leaving the agent to guess which tool fits a given scenario.

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