Use development tools to verify the complete function lifecycle.
1. Inspection
List registered functions and inspect generated metadata on a supported device. Compare actual identifiers with the ones your tests invoke.
2. Direct execution
Invoke the function through supported AppFunctions development tools with explicit parameters. Test domain behavior before adding an assistant-mediated conversation.
3. Failure diagnosis
Separate unsupported platform, missing registration, disabled function, bad arguments and domain denial. Each requires a different fix and user explanation.
Worked scenario
A direct invocation succeeds but an assistant cannot access the preview integration. That is not evidence that the function implementation failed.
Apply it
Write a reproducible discovery-and-execution transcript including success and invalid arguments.
Check your understanding
You can isolate platform availability from function correctness. Explain the decision and show evidence from your implementation or design. If you cannot demonstrate it yet, revisit the relevant section before continuing.