fix: shorten tool call IDs and fix duplicate tool name in truncated output filenames (#18600)

packages/core/src/core/turn.test.ts

@@ -168,7 +168,7 @@ describe('Turn', () => {
         }),
       );
       expect(event2.value.callId).toEqual(
-        expect.stringMatching(/^tool2-\d{13}-\w{10,}$/),
+        expect.stringMatching(/^tool2_\d{13}_\d+$/),
       );
       expect(turn.pendingToolCalls[1]).toEqual(event2.value);
       expect(turn.getDebugResponses().length).toBe(1);

packages/core/src/core/turn.ts

@@ -233,6 +233,8 @@ export type ServerGeminiStreamEvent =
 
 // A turn manages the agentic loop turn within the server context.
 export class Turn {
+  private callCounter = 0;
+
   readonly pendingToolCalls: ToolCallRequestInfo[] = [];
   private debugResponses: GenerateContentResponse[] = [];
   private pendingCitations = new Set<string>();
@@ -398,11 +400,9 @@ export class Turn {
     fnCall: FunctionCall,
     traceId?: string,
   ): ServerGeminiStreamEvent | null {
-    const callId =
-      fnCall.id ??
-      `${fnCall.name}-${Date.now()}-${Math.random().toString(16).slice(2)}`;
     const name = fnCall.name || 'undefined_tool_name';
     const args = fnCall.args || {};
+    const callId = fnCall.id ?? `${name}_${Date.now()}_${this.callCounter++}`;
 
     const toolCallRequest: ToolCallRequestInfo = {
       callId,