Press hardware/virtual key

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

No annotations are present, so the description is the only source of behavior. It discloses the core action (sending a keycode) and that it does not use vision, but it does not clarify whether the key is pressed and released with a single event or describe timing/duration. Lacks details on 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?

One compact sentence with two clauses; the key action is front-loaded, and each part (action, examples, vision exclusion) adds value without redundancy.

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?

Simple tool with one required parameter and no output schema. The description covers what it does and gives examples, so an agent can invoke it correctly. It does not explain return behavior or errors, but those are likely unnecessary for a fire-and-forget key event. Minor missing context about when to use it is covered under usage guidance.

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 documents keycode as an Android KEYCODE_* integer. The description adds specific example values (4=BACK, 66=ENTER, 187=APP_SWITCH), which clarify the range and meaning significantly beyond the schema's generic description.

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?

States the specific verb 'send' and resource 'Android keyevent code', gives concrete examples distinguishing it from vision-based siblings like screenshot_ask and tap_and_ask, and explicitly notes 'No vision call.'

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?

Provides minimal guidance on when to use; the 'No vision call' implies it is not for visual tasks, but it does not explicitly name alternatives or conditions for selection. The examples imply use for system keys but lack explicit routing.

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