ui.home

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

No annotations are provided, so the description carries the full behavioral burden, and it discloses nothing: not whether the current app is killed or backgrounded, whether state is preserved, whether the gesture works from any screen, or whether it can fail. For a UI-navigation action this is a significant gap.

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?

Four characters is front-loaded and waste-free, but it is under-specified rather than efficiently concise, and the description is in Chinese while all sibling tool names and identifiers are English, which adds a small parsing cost.

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 no-argument, no-output UI action the description is arguably sufficient to invoke it correctly, but it omits any note about failure conditions or interaction with the navigation stack, which is the only real risk with this tool.

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 tool takes zero parameters, so the baseline of 4 applies; there is nothing for the description to disambiguate beyond the action itself. Schema coverage is 100% trivially.

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 specific action and destination (return to the home/desktop screen), so an agent can tell what it does without opening the schema. It does not, however, distinguish itself from the nearest sibling ui.back, which also navigates away from the current view.

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 when-to-use guidance and no mention of alternatives such as ui.back or app.launch, even though those are the obvious competing ways to change screen state. The agent must infer the selection criteria entirely from the tool name.

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