press_key

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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false), so the description need not restate that. Beyond the list of key names it discloses nothing about behavior: no effect description, no requirement for a connected/foreground device, and no note on what happens on failure.

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?

A single front-loaded sentence with zero filler; every token is the actionable list of valid keys. Nothing is padded or redundant.

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?

An output schema exists, so return values need not be described, and annotations cover the safety profile. Still, for a 0%-coverage two-parameter tool the description omits the `serial` parameter entirely and gives no indication that a target device is required.

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 coverage is 0% and there are no enums, so the description carries real weight by enumerating the accepted values for `key` (back, home, recents, enter, delete, tab, volume_up/down, power, menu, search). However, the second parameter `serial` is entirely undocumented in both schema and description, leaving device targeting unexplained.

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 a specific verb (press) and enumerates the exact key values accepted, which makes the action unambiguous. It does not distinguish itself from siblings like tap_element, type_text, or tap, so an agent must infer that this issues hardware/navigation key events rather than touch or text input.

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?

There is no guidance on when to use this tool versus tap, tap_element, or type_text, and no stated prerequisites (e.g., an active device connection). The enumerated list implies valid inputs but gives no routing context or exclusions.

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