playwright_fill

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. 'Fill out an input field' implies a write operation but doesn't specify if it requires page interaction, handles errors (e.g., missing selector), or has side effects like triggering events. It lacks details on permissions, rate limits, or response format, which is inadequate for a mutation tool with zero annotation coverage.

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, efficient sentence ('Fill out an input field') that directly states the purpose without unnecessary words. It's appropriately sized and front-loaded, making it easy to parse quickly.

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 complexity of a web automation tool with no annotations and no output schema, the description is incomplete. It doesn't explain the return values, error handling, or interaction context (e.g., requires a loaded page). For a tool that performs mutations in a dynamic environment, more context is needed to ensure correct usage.

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% description coverage, with clear documentation for 'selector' (CSS selector) and 'value' (value to fill). The description doesn't add any meaning beyond this, such as examples or constraints, but the schema provides sufficient detail. According to the rules, with high schema coverage, the baseline is 3 even without extra param info in the description.

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 'Fill out an input field' clearly states the action (fill) and target (input field), which is better than a tautology. However, it lacks specificity about what kind of input field or context (e.g., web page, form) and doesn't distinguish it from potential sibling tools like playwright_click_text that might also interact with input fields. This makes it vague but functional.

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. It doesn't mention sibling tools like playwright_click or playwright_evaluate, nor does it specify prerequisites (e.g., needing a page loaded) or exclusions. This leaves the agent with minimal context for tool selection.

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