Press Button

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

Annotations declare readOnlyHint=false, so the operation may have side effects, but the description adds no behavioral context. It does not mention that pressing HOME, BACK, or VOLUME buttons can change device state or navigation. No contradiction exists, but no value is added beyond the annotations.

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 a single short sentence with no wasted words. It is concise and front-loads the core action, though it is perhaps too terse to provide useful disambiguation.

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 simple two-parameter tool with full schema coverage and annotations, the description is minimally viable. However, it leaves a gap around the hardware-button semantics and when to use it relative to screen-click tools, so it is not fully complete.

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%, and the button parameter already lists all supported values and device gives lookup guidance. The description itself adds no parameter-level meaning, so it meets the baseline for fully documented parameters.

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 states a clear action and resource: 'Press a button on device.' It is not fully tautological, but it does not explicitly say it handles hardware/system buttons rather than on-screen elements, so it lacks sibling differentiation from mobile_click_on_screen_at_coordinates.

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 alternatives such as mobile_click_on_screen_at_coordinates or mobile_type_keys. The supported button list in the schema hints at its purpose, but the description itself provides no usage context or exclusions.

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