arc_press_key

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

The description is minimal and does not disclose any behavioral traits beyond the basic action. With no annotations, it is adequate for a simple key press but lacks details about side effects, waiting, or constraints.

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 sentence in Japanese, which is concise and contains no extraneous information. However, it could be more informative while remaining concise.

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?

For a tool with 3 parameters and no output schema, the description lacks context such as what happens on invalid keys, whether it waits for page readiness, or how it interacts with the focused element. It is incomplete for reliable usage.

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 input schema already has complete descriptions for all three parameters (key, selector, tab_index). The description adds no additional meaning beyond what the schema provides, so baseline score applies.

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 (press) and the resource (key or key combination). It is specific about what the tool does, but does not differentiate it from sibling tools like arc_click or arc_hover that perform other input actions.

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 provides no guidance on when to use this tool versus alternatives. There is no mention of context, prerequisites, or conditions for pressing keys, nor any comparison with sibling tools.

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