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

No annotations provided, so description carries full burden. It discloses the mechanism (keycode 187 APP_SWITCH shell, policy-gated), the wait-for-settle behavior, the locates-and-swipes approach, and the return shape ({ success, action, ... }). This is rich behavioral disclosure for a side-effecting UI automation tool.

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?

Three sentences, front-loaded with the core action, followed by use cases and mechanism detail. Slightly verbose with implementation specifics (keycode 187, policy-gated) that could arguably be trimmed, but each clause earns its place for transparency.

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?

Complete for a 3-param tool with 100% schema coverage and no output schema. The description covers the mechanism, the use case, the return shape, the optional all flag behavior, and default packageName behavior. No meaningful gaps remain for an agent to correctly select and invoke 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?

Schema coverage is 100% with each parameter well-documented ('Tap Close all instead of swiping a single card', 'package name... If omitted, dismisses the first/frontmost card'). The description adds marginal context by mentioning the return includes an action field, but parameters are fully explained by the schema, so baseline 3 applies.

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?

Specific verb+resource: opens Recents, dismisses an app card via swipe, with optional 'Close all'. Clearly distinguishes from siblings like device_terminate_app (which kills directly) and device_swipe (generic swipe) by naming keycode 187 (APP_SWITCH). The intent is unambiguous.

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?

States clear use cases: 'clearing background apps or verifying an app was killed.' Implicitly distinguishes from device_terminate_app (which terminates in-process rather than via Recents UI). Doesn't explicitly name an alternative when NOT to use it, but the context is clear.

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