Press Button

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

Annotations already indicate destructiveHint: true, so the description does not need to repeat that. The description adds no further behavioral details (e.g., effect on app state, permissions required). It is consistent with annotations but provides no extra value beyond them.

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 very concise (one short sentence) and front-loaded with the core action. It does not waste words, though it could be slightly expanded to include context without becoming verbose.

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?

Given that there is no output schema and the tool is destructive (destructiveHint true), the description lacks details about return values, side effects, or prerequisites. For a simple tool with only two parameters, it is minimally adequate but leaves out important contextual information.

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 input schema provides 100% coverage with descriptions for both parameters. The tool description adds no additional meaning beyond the schema. Per guidelines, baseline is 3 when schema coverage is high.

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 'Press a button on device' clearly states the action and resource. It effectively distinguishes from sibling tools like mobile_click_on_screen_at_coordinates or mobile_type_keys by specifying a physical button press. However, it could be slightly more specific about the context (e.g., hardware vs software buttons).

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 is provided on when to use this tool versus alternatives. The description does not mention prerequisites, conditions, or when not to use it. Given the sibling tools, explicit usage guidelines would help the agent decide correctly.

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