Add toolUsePromptTokenCount and toolUsePromptTokensDetails

Author: andrewheard

FirebaseAI/Sources/GenerateContentResponse.swift

@@ -26,6 +26,9 @@ public struct GenerateContentResponse: Sendable {
     /// The total number of tokens across the generated response candidates.
     public let candidatesTokenCount: Int
 
+    /// The number of tokens present in tool-use prompt(s).
+    public let toolUsePromptTokenCount: Int
+
     /// The number of tokens used by the model's internal "thinking" process.
     ///
     /// For models that support thinking (like Gemini 2.5 Pro and Flash), this represents the actual
@@ -44,6 +47,9 @@ public struct GenerateContentResponse: Sendable {
 
     /// The breakdown, by modality, of how many tokens are consumed by the candidates
     public let candidatesTokensDetails: [ModalityTokenCount]
+
+    /// List of modalities that were processed for tool-use request inputs.
+    public let toolUsePromptTokensDetails: [ModalityTokenCount]
   }
 
   /// A list of candidate response content, ordered from best to worst.
@@ -474,17 +480,21 @@ extension GenerateContentResponse.UsageMetadata: Decodable {
   enum CodingKeys: CodingKey {
     case promptTokenCount
     case candidatesTokenCount
+    case toolUsePromptTokenCount
     case thoughtsTokenCount
     case totalTokenCount
     case promptTokensDetails
     case candidatesTokensDetails
+    case toolUsePromptTokensDetails
   }
 
   public init(from decoder: any Decoder) throws {
     let container = try decoder.container(keyedBy: CodingKeys.self)
     promptTokenCount = try container.decodeIfPresent(Int.self, forKey: .promptTokenCount) ?? 0
     candidatesTokenCount =
       try container.decodeIfPresent(Int.self, forKey: .candidatesTokenCount) ?? 0
+    toolUsePromptTokenCount =
+      try container.decodeIfPresent(Int.self, forKey: .toolUsePromptTokenCount) ?? 0
     thoughtsTokenCount = try container.decodeIfPresent(Int.self, forKey: .thoughtsTokenCount) ?? 0
     totalTokenCount = try container.decodeIfPresent(Int.self, forKey: .totalTokenCount) ?? 0
     promptTokensDetails =
@@ -493,6 +503,9 @@ extension GenerateContentResponse.UsageMetadata: Decodable {
       [ModalityTokenCount].self,
       forKey: .candidatesTokensDetails
     ) ?? []
+    toolUsePromptTokensDetails = try container.decodeIfPresent(
+      [ModalityTokenCount].self, forKey: .toolUsePromptTokensDetails
+    ) ?? []
   }
 }