diff --git a/src/agents/pi-embedded-helpers.sanitizeuserfacingtext.e2e.test.ts b/src/agents/pi-embedded-helpers.sanitizeuserfacingtext.e2e.test.ts
index 4d9817f59f6..ee24dac096d 100644
--- a/src/agents/pi-embedded-helpers.sanitizeuserfacingtext.e2e.test.ts
+++ b/src/agents/pi-embedded-helpers.sanitizeuserfacingtext.e2e.test.ts
@@ -191,9 +191,6 @@ describe("sanitizeToolCallId", () => {
     it("strips invalid characters", () => {
       expect(sanitizeToolCallId("call_abc|item:456")).toBe("callabcitem456");
     });
-    it("returns default for empty IDs", () => {
-      expect(sanitizeToolCallId("")).toBe("defaulttoolid");
-    });
   });
 
   describe("strict mode (alphanumeric only)", () => {
@@ -204,9 +201,6 @@ describe("sanitizeToolCallId", () => {
         "whatsapplogin17687998415271",
       );
     });
-    it("returns default for empty IDs", () => {
-      expect(sanitizeToolCallId("", "strict")).toBe("defaulttoolid");
-    });
   });
 
   describe("strict9 mode (Mistral tool call IDs)", () => {
@@ -214,9 +208,26 @@ describe("sanitizeToolCallId", () => {
       const out = sanitizeToolCallId("call_abc|item:456", "strict9");
       expect(out).toMatch(/^[a-zA-Z0-9]{9}$/);
     });
-    it("returns default for empty IDs", () => {
-      expect(sanitizeToolCallId("", "strict9")).toMatch(/^[a-zA-Z0-9]{9}$/);
-    });
+  });
+
+  it.each([
+    {
+      modeLabel: "default",
+      run: () => sanitizeToolCallId(""),
+      assert: (value: string) => expect(value).toBe("defaulttoolid"),
+    },
+    {
+      modeLabel: "strict",
+      run: () => sanitizeToolCallId("", "strict"),
+      assert: (value: string) => expect(value).toBe("defaulttoolid"),
+    },
+    {
+      modeLabel: "strict9",
+      run: () => sanitizeToolCallId("", "strict9"),
+      assert: (value: string) => expect(value).toMatch(/^[a-zA-Z0-9]{9}$/),
+    },
+  ])("returns default for empty IDs in $modeLabel mode", ({ run, assert }) => {
+    assert(run());
   });
 });