press_key

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

With no annotations, the description carries the burden of behavioral disclosure. It adds useful context about how key names are transformed (KEYCODE_ prefix) and platform support, but it does not describe return values, error conditions (e.g., unsupported iOS keys), or side effects.

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 core purpose, and uses clear structure to separate Android and iOS behavior. There is no redundant or irrelevant information.

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 two-parameter schema, no annotations, and presence of an output schema, the description is reasonably informative but missing some context: it does not mention what the tool returns, how errors are surfaced, or whether this tool should be preferred over the dedicated press_back/press_home siblings for specific use cases.

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. It adds meaning for the 'key' parameter by listing accepted formats on Android and iOS, but it does not explain the 'device' parameter (e.g., device ID or name). Partial compensation is provided, but not complete.

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 sends a platform key event, with a specific verb and resource. It is distinguishable from sibling tools like press_back and press_home by covering generic keys, but it does not explicitly differentiate itself from those dedicated key-press tools.

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?

Usage context is implied by the platform-specific key names (Android KEYCODE_* and iOS HOME/ENTER/BACK), but there is no explicit guidance on when to use this tool versus the dedicated press_back/press_home alternatives. The description does not mention exclusions or alternative tools.

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