playwright_fill

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only says 'fill a form field' without revealing whether it clears existing values, triggers events, waits for visibility, or affects the page state. Essential behavioral traits are missing.

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 concise sentence with no redundant words. It front-loads the core action and includes all essential elements without waste.

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 simple fill operation, the description covers the basic function but omits behavioral nuances like field clearing, event triggering, or visibility requirements. The presence of an output schema is not leveraged, but for this straightforward tool the description is minimally adequate.

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 description adds 'CSS selector' for the 'selector' parameter, giving useful type information beyond the schema's bare title. However, the 'value' parameter is only described as 'a value', providing minimal extra meaning. With 0% schema coverage, the description partially compensates but remains thin.

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 action ('Fill a form field') with a specific resource ('form field') and additional detail ('CSS selector'), distinguishing it from sibling tools like click or navigate. The verb is precise and the scope is unambiguous.

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 phrase 'in the interactive session' provides some contextual hint about when to use this tool (after navigation, in a live browser session), but it does not explicitly state alternatives or when not to use it. The usage is implied rather than explicit.

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