browser_keyboard_down

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

With no annotations, the description must carry the full burden. '按下' implies a key-down event, but it does not state that the key is held down until a corresponding keyboard_up call, nor does it mention focus requirements or modifier key behavior. The minimal wording provides only vague behavioral disclosure.

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 phrase with no wasted words. It is front-loaded and appropriately sized for a tool with one parameter, but it is so minimal that conciseness comes at the expense of clarity.

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 has a simple schema and no output schema, but the description still needs to clarify the key format, the relationship with keyboard_up, and when to use it instead of browser_press. All of this is missing, making the description insufficient for reliable invocation.

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 defines only 'key' as a required string, but neither the schema nor the description explains the expected format (e.g., 'Enter', 'a', or 'Control'). Schema description coverage is 0%, and the description adds no meaning to the parameter.

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 '按下键盘按键' translates to 'Press keyboard key'. It uses a specific verb and resource, but does not explicitly distinguish the 'down' action from a full key press, especially given the sibling tool browser_press. The language mismatch (Chinese vs English tool name) may also reduce clarity for some agents.

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 is provided on when to use this tool versus alternatives like browser_keyboard_up, browser_press, or browser_keyboard_insert_text. There are no exclusions or context cues.

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