iOS 18: Siri not passing string parameters to AppIntents if the string is a question

Xcode Version 16.0 (16A242d)

iOS18 - Swift

There seems to be a behavior change on iOS18 when using AppShortcuts and AppIntents to pass string parameters. After Siri prompts for a string property requestValueDialog, if the user makes a statement the string is passed. If the user's statement is a question, however, the string is not sent to the AppIntent and instead Siri attempts to answer that question.

Example Code:

struct MyAppNameShortcuts: AppShortcutsProvider {
  @AppShortcutsBuilder
  static var appShortcuts: [AppShortcut] {
    AppShortcut(
      intent: AskQuestionIntent(),
      phrases: [
        "Ask \(.applicationName) a question",
      ]
    )
  }
}

struct AskQuestionIntent: AppIntent {
  static var title: LocalizedStringResource = .init(stringLiteral: "Ask a question")
  static var openAppWhenRun: Bool = false
  static var parameterSummary: some ParameterSummary {
    Summary("Search for \(\.$query)")
  }
 
  @Dependency
  private var apiClient: MockApiClient
 
  @Parameter(title: "Query", requestValueDialog: .init(stringLiteral: "What would you like to ask?"))
  var query: String
 
  // perform is not called if user asks a question such as "What color is the moon?" in response to requestValueDialog
  // iOS 17, the same string is passed though
  @MainActor
  func perform() async throws -> some IntentResult & ProvidesDialog & ShowsSnippetView {
    print("Query is: \(query)")
    let queryResult = try await apiClient.askQuery(queryString: query)
    let dialog = IntentDialog(
      full: .init(stringLiteral: queryResult.answer),
      supporting: .init(stringLiteral: "The answer to \(queryResult.question) is...")
    )
    let view = SiriAnswerView(queryResult: queryResult)
    return .result(dialog: dialog, view: view)
  }
}

Given the above mock code:

iOS17:

• Hey Siri
• Ask (AppName) a question
• Siri responds "What would you like to ask?"
• Say "What color is the moon?"
• String of "What color is the moon?" is passed to the AppIntent

iOS18:

• Hey Siri

• Ask (AppName) a question

• Siri responds "What would you like to ask?"

• Say "What color is the moon?"

• Siri answers the question "What color is the moon?"

• Follow above steps again and instead reply "Moon"

• "Moon" is passed to AppIntent

Basically any interrogative string parameters seem to be intercepted and sent to Siri proper rather than the provided AppIntent in iOS 18