fill_by_label

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

With no annotations, the description carries full burden. It does not disclose what happens if the label is missing, whether it clears the input before filling, or if it triggers events. The minimal description provides negligible behavioral insight.

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 short sentence, which is concise but at the expense of necessary detail. It is not verbose, but fails to include key information, making it under-specified rather than efficiently concise.

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 two parameters, no annotations, and an output schema (not shown), the description is incomplete. It does not mention the return value or error conditions. More context about the tool's behavior and constraints is needed for complete understanding.

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 coverage is 0%, so the description must compensate. It merely echoes parameter names ('label', 'value') without adding any explanation or constraints. The description adds zero semantic value beyond the field 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 description 'Fill input found by its label' clearly states the action (fill) and the resource (input by label). It distinguishes from siblings like 'fill' which likely uses a different locator strategy. However, it could be more explicit about the label-based selection.

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 this tool over alternatives like 'fill' or 'type_text'. There is no mention of prerequisites (e.g., element must exist) or context where using a label is preferred.

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