browse_fill

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

With no annotations, the description carries the full behavioral burden. It does disclose that the existing value is overwritten and that Enter can be pressed afterwards, but it says nothing about whether the element is focused/waited for, whether the field is cleared first, or what happens if the selector matches nothing.

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?

A single front-loaded sentence with no filler. It is efficient, though its brevity reflects under-specification rather than tight writing.

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 mutation tool with zero annotations, no output schema, and 0% schema coverage, the description should cover selector format, clearing semantics, and failure behavior. None of that is present, so an agent cannot be confident about invoking it correctly.

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 all three parameters depend on the description. It explains the meaning of value (replaces) and press_enter (press Enter afterwards), but leaves selector completely undefined — no CSS/XPath syntax, no guidance on what it matches — which is the parameter most likely to be misused.

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 specific verb and resource: "Replace an input's value" plus the optional Enter behavior. This is clear enough to act on, but it never distinguishes itself from the sibling browse_type, which an agent will likely confuse it with (replace vs. type/append).

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?

No guidance on when to use browse_fill instead of browse_type or browse_select_option. The only implied condition is 'the target is a text input,' which the agent has to infer from the word 'input.'

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