System search AssistantIntent not working

@available(iOS 18.0, *)
@AssistantIntent(schema: .system.search)
struct SearchIntent: AppIntent {
  static let title: LocalizedStringResource = "Search <app name redacted>"
  static let searchScopes: [StringSearchScope] = [.general]

  @Parameter(title: "Criteria")
  var criteria: StringSearchCriteria

  @MainActor
  func perform() async throws -> some IntentResult {
    MyDependencyManager.shared.performSearch(with: criteria.term)
    return .result()
  }
}

// In AppShortcutProvider

AppShortcut(
  intent: SearchIntent(),
  phrases: [
   "Find \(\.$criteria) in \(.applicationName)",
    "Search for \(\.$criteria) in \(.applicationName)",
  ],
  shortTitle: "Search <app name redacted>",
  systemImageName: "magnifyingglass"
)

The search works when using the Shortcuts app, but not when using Siri. For example if I ask Siri "Search for <thing> in <app name>" it just does a Google search or prompts me to install the app from the App Store (I am running a debug build via Xcode). I can't get this to work from Spotlight either.

I am using Xcode 16 and running the app on an iPhone 16 with OS 18.2 beta and Apple Intelligence turned on.

What am I doing wrong here? I cannot find any other information about this intent or how to properly set it up and use it.