Android AppFunctions are indexed/enabled on device but Gemini cannot resolve custom function metadata

[lates-codrin]

Description of the bug

I integrated Android AppFunctions in a third-party app and verified that the platform indexes and enables all functions. However, Gemini does not discover or execute these functions and logs metadata resolution failures.

Environment

• Device: Samsung Galaxy A34 (SM-A346B)
• Android: 16 (SDK 36)
• Build tools: AGP 8.9.1, Gradle 8.14.3
• Language/tooling: Kotlin 2.1.10, KSP 2.1.10-1.0.31
• Libraries:
  • androidx.appfunctions:appfunctions:1.0.0-alpha07
  • androidx.appfunctions:appfunctions-service:1.0.0-alpha07
  • androidx.appfunctions:appfunctions-compiler:1.0.0-alpha07

What was validated already

• KSP aggregation is enabled: appfunctions:aggregateAppFunctions=true
• APK includes required assets:
  • assets/app_functions.xml
  • assets/app_functions_v2.xml
  • assets/app_functions_schema.xsd
• Manifest contains merged AppFunction services/properties.
• Device has com.android.extensions.appfunctions library.
• dumpsys app_function shows all six functions with runtime metadata and enabled: [1].
• App-side diagnostics report 6/6 functions indexed.

Minimal reproduction

1. Build and install app on Android 16 device.
2. Launch app and wait for AppFunction registration/indexing.
3. Confirm indexed state via dumpsys app_function and app logs.
4. Attempt discovery/execution through Gemini.

Actual vs expected behavior

Actual behavior

• Gemini does not discover/execute the custom app functions.
• Logs repeatedly show: D/AppFunctions: Unable to resolve AppFunctionMetadata.

Expected behavior

• Once functions are indexed and enabled by the Android AppFunctions platform, Gemini should discover and be able to execute them, or provide a clear compatibility reason if custom schemas are unsupported.

Any other information you'd like to share?

• This may be a support/compatibility question rather than a pure runtime bug.
• If custom app-defined schemas are not currently supported in Gemini, please confirm current limitations and any roadmap for support.