browser_fill

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

There are no annotations. The description mentions simulating real user input with a delay, which provides some behavioral insight, but it does not disclose side effects such as the default clearing behavior (though that is in the schema) or whether the action is reversible. Since no annotations are present, the description carries full responsibility and falls short of full transparency.

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 concise and directly stated in two short sentences. It includes the essential action and a key behavioral characteristic (delay) without unnecessary detail, making it 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?

Given the tool's moderate complexity (four parameters) and lack of an output schema, the description together with the schema provides enough context for an agent to call it correctly. It does not explain return values, but that is not strictly necessary since the tool likely returns nothing or a simple confirmation.

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 schema provides complete descriptions for all four parameters (selector, value, clear, delayMs), offering 100% coverage. The description adds no extra semantic meaning beyond what the schema already defines, so it meets the baseline but does not improve it.

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 clearly states the tool's purpose: to fill an input box with simulated real user input, including a delay. This distinguishes it from sibling tools like browser_click, browser_clear, and browser_pressKey, which have different actions.

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 implies the tool is for filling text inputs but does not explicitly explain when to use it over alternatives like browser_pressKey or browser_clear. No use-case guidance is provided, so the agent must infer the appropriate context.

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