fill_input

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

With no annotations provided, the description fully carries the behavioral transparency burden. It discloses crucial behaviors: empty value clears the field, type triggers keyboard events, fill uses native filling, clear_first defaults to clearing, press_enter can be enabled, and visualize has a three-state behavior. It also reveals the return structure (visual_effects + observation), giving a clear picture of what happens.

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 dense paragraph packed with information, with no filler or redundant words. It front-loads the purpose and then efficiently lists parameter behaviors. While concise, it could benefit from bullet points or separation for easier scanning, but every sentence earns its place.

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 11 parameters, no annotations, and an output schema, the description covers the core behaviors, input methods, return structure, and most parameters. It lacks explanation for 'description' and 'expected_result', and provides no error-handling or failure behavior, but for the typical use case it is fairly complete. The output schema handles return-value details.

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%, so the description must compensate, and it does for most parameters: by, selector, iframe_selector, value, input_method, clear_first, press_enter, detail, and visualize all receive explanations. However, 'description' and 'expected_result' parameters are not mentioned, leaving a small gap. It adds significant semantic value beyond the bare schema.

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 '文本框输入工具' (text box input tool) and details the mechanism for targeting elements via by/selector, including iframe penetration. It distinguishes itself from siblings focused on clicks or table operations, though it doesn't explicitly name alternatives. The purpose 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 description implies usage contexts by explaining input methods (type vs fill), clear_first behavior, and press_enter, but does not explicitly state when to choose this tool over siblings or when not to use it. It provides parameter-level guidance but lacks strategic usage direction. No alternatives are named.

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