press_key

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

With no annotations provided, the description reveals the mechanism ('ephemeral Maestro flow') and platform limitation (iOS only). It lists valid keys but does not disclose side effects (e.g., pressing home exits app) or error behavior.

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: the first states the core function, the second adds a critical caveat. It is front-loaded, concise, and contains no unnecessary words.

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 5 parameters (3 required) and no output schema or annotations. The description covers the main behavior and a key platform limitation, but lacks details on error conditions, prerequisites (e.g., device must be booted), or what happens on failure. It is minimally complete for a simple action.

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 100%, so the baseline is 3. The description adds value by explaining the Android key caveat and the purpose of noLaunch, but does not elaborate on timeoutMs or other parameters beyond schema.

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 ('Presses'), the resource ('hardware or system key'), and the context ('via an ephemeral Maestro flow on the iOS simulator'). It distinguishes from sibling tools (e.g., tap_on, swipe) by specifying it deals with hardware/system 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 warns that back/power/tab are Android key events with no effect on iOS, providing partial guidance on when not to use certain keys. However, it does not explicitly state when to use this tool vs. alternatives like tap_on or input_text.

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