键入文本

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

With no annotations, the description carries the burden of disclosure. It transparently notes '发送键盘事件到当前页面' (sends keyboard events to the current page) and states the target is the focused element. However, it does not mention behavior when no element is focused, whether existing content is overwritten, or error conditions.

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 extremely concise: two short sentences, the first stating the action and the second clarifying permissions. It is front-loaded with the core purpose and contains no redundant or filler text.

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 simplicity (2 params, no output schema), the description provides necessary context about the target (focused element) and mechanism (keyboard events). However, it lacks explicit guidance on when to use this versus web_fill or web_press, which are closely related siblings, so it is not fully complete.

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 schema already covers both parameters with descriptions (100% coverage). The description adds value by explicitly connecting the delay parameter to the purpose of simulating real input rhythm ('可模拟真实输入节奏'), which enriches the parameter meaning beyond the schema's technical specification.

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 verb '键入' (type) and resource '当前聚焦元素' (currently focused element), and specifies the method '逐键输入' (key-by-key). This distinguishes it from sibling tools like web_fill (which likely fills a field directly) and web_press (which sends a single key press).

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?

It explicitly states that typing targets the currently focused element, providing clear context that the element must be focused first. It also mentions the ability to simulate real input rhythm, implying when this is useful. However, it does not explicitly name alternatives or exclusion criteria.

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