Type text into the focused control

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

Annotations are sparse (all hints false) and do not disclose safety or side effects. The description adds context about 'plain text' and 'focused control', implying a non-interpretive typing action. It does not explain behaviors such as whether existing text is replaced, what happens if no control is focused, or that interval_ms controls typing speed. Since annotations provide little, the description carries the burden but only partially covers behavioral traits.

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 two sentences, front-loaded with the primary purpose and followed by a concise safety warning. Every word earns its place, with no redundancy or filler. The structure is ideal for quick comprehension.

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?

The tool is simple with only 2 parameters, and the output schema exists (though not shown), so return value documentation is covered. The description conveys the core action and a critical security constraint. However, it omits the prerequisite that a control must already be focused, which is important for correct usage in an agent context. It also does not mention any potential failure modes when typing into non-text fields.

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% and the description does not explain either parameter. While 'text' is somewhat self-evident from the tool's purpose, 'interval_ms' is only documented in the schema with a default of 12, giving no indication of its effect (e.g., delay between keystrokes). The description should compensate for the lack of schema descriptions but does not.

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 tool's function with a specific verb and object: 'Type bounded plain text into the currently focused control.' This distinguishes it from sibling tools like click, press_key, and scroll, which handle different input modalities. The phrase 'bounded plain text' also clarifies the text is not interpreted as commands or special keys.

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 gives clear context: the tool types text into the currently focused control. It also includes an explicit 'Never' list (passwords, tokens, recovery codes, payment data, terminal commands) which serves as a when-not guideline for sensitive content. However, it does not name alternative sibling tools or explicitly compare when to use this tool versus press_key or other input methods, so it falls short of a 5.

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