Fill page field

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

No annotations are provided, and the description does not disclose behavioral details such as side effects, event triggering, element visibility requirements, or error handling. The 'compatibility' label hints at being legacy but doesn't explain behavior.

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?

Two short sentences, front-loaded with the core purpose and immediately followed by actionable alternative guidance. Every word earns its place; no redundancy.

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 simplicity, the description still lacks essential context: no return value, no error conditions, no prerequisites (e.g., element must exist), and no schema descriptions to fill in the gaps. The explicit alternative helps, but the tool remains under-specified for a robust agent invocation.

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%, and the description only says 'selector-based fill', which implies the selector is a CSS-style selector but doesn't explain tabId or value semantics, value format, or length constraints. It adds minimal meaning beyond the parameter names.

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 title 'Fill page field' and description 'Compatibility selector-based fill' clearly state the tool fills a field using a selector. It also distinguishes itself as a compatibility path by pointing to browser_act for new workflows.

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 explicitly states 'New workflows should use browser_snapshot refs with browser_act', providing a clear when-not-to-use and a named alternative. This is strong guidance for tool selection.

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