Android Knowledge Base first → Targeted Skills second → Custom Skills third

// ❌ WITHOUT Navigation 2.8+ skill — Legacy / String-Based (Pre-2.8)  
  
val navController = rememberNavController()  
NavHost(navController = navController, startDestination = "home") {  
    composable("home") {  
        HomeScreen(  
            onNavigateToDetail = { userId ->  
                navController.navigate("detail/$userId")  
            }  
        )  
    }  
    composable(  
        route = "detail/{userId}",  
        arguments = listOf(navArgument("userId") {  
            type = NavType.StringType  
        })  
    ) { backStackEntry ->  
        DetailScreen(  
            userId = backStackEntry.arguments  
                ?.getString("userId") ?: ""  
        )  
    }  
}

// ✅ WITH Navigation 2.8+ skill — Modern Type-Safe (2.8.0+)  
  
@Serializable   
object Home  
  
@Serializable   
data class Detail(val userId: String)  
  
val navController = rememberNavController()  
  
NavHost(  
    navController = navController,  
    startDestination = Home  
) {  
    composable<Home> {  
        HomeScreen(  
            onNavigateToDetail = { userId ->  
                navController.navigate(Detail(userId = userId))  
            }  
        )  
    }  
      
    composable<Detail> { backStackEntry ->  
        val detail: Detail = backStackEntry.toRoute()  
        DetailScreen(userId = detail.userId)  
    }  
}

timeout_s: 1200  
repository:  
  working_dir: wear_compose_m3_empty_app  
prompt: |-  
  Add a horizontal pager to MainActivity.kt with three pages   
  showing "Page 1", "Page 2", "Page 3" centered on screen.  
commands:  
  build:  
    - ./gradlew assembleDebug  
acceptance_criteria:  
  project_builds: true  
  llm_diff_judge:  
    - Must use `HorizontalPagerScaffold`  
    - Each page must use `AnimatedPage` wrapping `ScreenScaffold`

# AGENTS.md  
  
## Documentation  
Always consult the Android Knowledge Base (android docs)   
before suggesting any Jetpack API.  
  
## Architecture  
- MVVM + Hilt — do NOT suggest Koin or manual DI  
- ViewModels use StateFlow — never LiveData for new code  
- Repository pattern required for all data access  
  
## UI  
- All new screens use Jetpack Compose — no new XML layouts  
- Reference HomeScreen.kt as the Compose pattern for this project  
  
## Navigation  
- Navigation 3 with type-safe routes — not navigation-compose 2.x  
- All routes must be @Serializable — reference NavGraph.kt  
  
## Build  
- AGP 9 — use libs.versions.toml, no direct build.gradle.kts deps  
  
## Testing  
- JUnit 5 + MockK for unit tests — not Mockito or Espresso  
- Coroutine tests use runTest from kotlinx-coroutines-test  
  
## Never  
- Thread.sleep() → use delay()  
- GlobalScope → use viewModelScope  
- Broad catch(Exception) → handle specific types  
- !! operator → handle nullability explicitly

// ❌ Agent adding to a legacy screen WITHOUT modernisation skill  
// Prompt: "Add an order history section to the user screen"  
// Agent sees surrounding LiveData code and matches it  
  
viewModel.orderHistory.observe(viewLifecycleOwner) { orders ->  
    binding.orderCount.text = "Orders: ${orders.size}"  
    binding.lastOrder.text = orders.firstOrNull()?.date ?: "None"  
}  
  
// ✅ Agent WITH a custom legacy migration skill  
// Produces Compose alongside legacy code instead  
  
binding.composeContainer.setContent {  
    val orders by viewModel.orderHistory  
        .collectAsStateWithLifecycle()  
    AppTheme {  
        OrderHistorySection(orders = orders)  
    }  
}

# 1. Install Android CLI from d.android.com/tools/agents  
  
# 2. Test Knowledge Base first — you may not need a skill  
android docs search "Navigation 3 type-safe routes"  
  
# 3. Install only confirmed-necessary skills  
android skills install navigation3   # Only if using Nav 3  
android skills install edge-to-edge  # Only if targeting API 35+  
android skills install agp9          # Only if on AGP 9  
  
# 4. Quarterly — remove skills your model no longer needs  
android skills list --installed