aua_press_button

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

Annotations already declare readOnlyHint=false, idempotentHint=false and openWorldHint=true, so the mutating, non-repeatable nature is covered structurally. The description adds real value by warning that Enter may submit something and requires user authorization, which is not in the annotations. It says nothing about the observation or wait side effects the tool can trigger.

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?

Two short sentences with the core action front-loaded and no filler. The second sentence is well placed as a safety caveat, though the phrasing is terse to the point of being cryptic about what 'authorize' requires.

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 3-parameter tool with a nested WaitCondition and no output schema, the description leaves two of three parameters undocumented and never explains what the call returns or how waiting/observation interact with the press. It covers the action and its risk but not the tool's full surface.

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 carries the full burden, yet it only partially enumerates the 'name' enum and never explains the 'observe' (none/tree/screenshot/both) or 'wait_for' (selector + state + timeout) parameters. An agent cannot learn from the text that a press can also return a UI tree or screenshot or block until a condition holds.

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 names the concrete buttons: home/back/recent/enter/volume. It is distinguishable from siblings like aua_tap or aua_long_press, which act on screen elements rather than hardware/navigation keys. It slightly underspecifies by lumping volume_up/volume_down under 'volume'.

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?

No guidance on when to choose this over aua_tap, aua_screen_action, or aua_type_text, and no prerequisites beyond a passing note that Enter requires user authorization. The agent must infer that this is the tool for hardware/nav keys rather than screen coordinates.

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