homeScreen

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

No annotations are provided, so the description carries the full burden. It mentions pressing the home button but fails to disclose behavioral traits like whether this action is safe (e.g., read-only vs. destructive), if it requires specific device states, or what happens post-execution (e.g., screen changes). This leaves significant gaps for an agent.

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, efficient sentence that directly states the action and method without unnecessary details. It is front-loaded and wastes no words, making it highly concise and well-structured.

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 the tool's low complexity (one parameter with full schema coverage) and no output schema, the description is minimally adequate but incomplete. It lacks details on behavioral outcomes (e.g., what 'returning to home screen' entails) and doesn't compensate for the absence of annotations, leaving room for improvement.

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 has 100% description coverage, with the 'platform' parameter fully documented in the schema. The description adds no additional meaning about parameters beyond implying device interaction, so it meets the baseline for high schema coverage without compensating further.

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 ('Return to the home screen') and the method ('by pressing the home button'), making the purpose specific and understandable. However, it does not explicitly differentiate from sibling tools like 'recentApps' or 'pressButton', which could have overlapping functionality, so it doesn't reach the highest score.

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 provides no guidance on when to use this tool versus alternatives, such as 'recentApps' for app switching or 'pressButton' for generic button presses. It lacks explicit context, prerequisites, or exclusions, leaving usage unclear.

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