fill

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

No annotations are provided, so the description carries full burden. It discloses a write operation ('fill text') but does not mention preconditions, side effects, or behavioral characteristics (e.g., whether it clears existing text, requires focus, or works only on input fields). The schema's many parameters are not addressed for behavioral implications.

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 sentence, front-loading the action and targeting methods. It is efficient with no waste, though it could be slightly expanded for clarity on the distinction from siblings.

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 complexity (22 parameters, no output schema, no annotations), the description is too minimal. It does not address the purpose of many parameters, expected behavior, or return information. The description is incomplete for effective use without additional documentation.

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 100%, so each parameter is already documented. The description adds value by summarizing the three targeting methods, but does not add meaning beyond the schema for other parameters. Baseline 3 is appropriate.

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 text into a semantic UI target) and the three targeting methods (ref, selector, point). It distinguishes from siblings like 'type' by specifying 'fill text', but does not explicitly contrast with 'type' which also inputs text. The verb 'fill' implies populating a field, which is slightly different but not fully clarified.

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 vs. alternatives like 'type' or 'click'. No when-not-to-use conditions. The description implies usage when you need to input text into a target, but lacks explicit context or exclusion criteria.

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