diff --git a/src/agents/pi-embedded-helpers.sanitize-session-messages-images.removes-empty-assistant-text-blocks-but-preserves.test.ts b/src/agents/pi-embedded-helpers.sanitize-session-messages-images.removes-empty-assistant-text-blocks-but-preserves.test.ts
index 5dea8251006..603475125d8 100644
--- a/src/agents/pi-embedded-helpers.sanitize-session-messages-images.removes-empty-assistant-text-blocks-but-preserves.test.ts
+++ b/src/agents/pi-embedded-helpers.sanitize-session-messages-images.removes-empty-assistant-text-blocks-but-preserves.test.ts
@@ -194,26 +194,13 @@ describe("sanitizeSessionMessagesImages", () => {
   });
   it("filters whitespace-only assistant text blocks", async () => {
     const input = castAgentMessages([
-      {
-        role: "assistant",
-        content: [
+      makeOpenAiResponsesAssistantMessage(
+        [
           { type: "text", text: "   " },
           { type: "text", text: "ok" },
         ],
-        api: "openai-responses",
-        provider: "openai",
-        model: "gpt-5.4",
-        usage: {
-          input: 0,
-          output: 0,
-          cacheRead: 0,
-          cacheWrite: 0,
-          totalTokens: 0,
-          cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
-        },
-        stopReason: "stop",
-        timestamp: nextTimestamp(),
-      },
+        "stop",
+      ),
     ]);
 
     const out = await sanitizeSessionMessagesImages(input, "test");
@@ -225,23 +212,7 @@ describe("sanitizeSessionMessagesImages", () => {
   it("drops assistant messages that only contain empty text", async () => {
     const input = castAgentMessages([
       { role: "user", content: "hello", timestamp: nextTimestamp() } satisfies UserMessage,
-      {
-        role: "assistant",
-        content: [{ type: "text", text: "" }],
-        api: "openai-responses",
-        provider: "openai",
-        model: "gpt-5.4",
-        usage: {
-          input: 0,
-          output: 0,
-          cacheRead: 0,
-          cacheWrite: 0,
-          totalTokens: 0,
-          cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
-        },
-        stopReason: "stop",
-        timestamp: nextTimestamp(),
-      } satisfies AssistantMessage,
+      makeOpenAiResponsesAssistantMessage([{ type: "text", text: "" }], "stop"),
     ]);
 
     const out = await sanitizeSessionMessagesImages(input, "test");