diff --git a/src/cron/isolated-agent/run.cron-model-override.test.ts b/src/cron/isolated-agent/run.cron-model-override.test.ts
index f4ffe1afe093..1ef53b251c3a 100644
--- a/src/cron/isolated-agent/run.cron-model-override.test.ts
+++ b/src/cron/isolated-agent/run.cron-model-override.test.ts
@@ -175,15 +175,17 @@ describe("runCronIsolatedAgentTurn — cron model override (#21057)", () => {
 
     expect(result.status).toBe("error");
     expect(result.error).toContain("Model not allowed");
-    expect(result.diagnostics).toMatchObject({
-      summary: expect.stringContaining("Model not allowed"),
-      entries: [
-        expect.objectContaining({
-          source: "cron-preflight",
-          severity: "error",
-          message: expect.stringContaining("Model not allowed"),
-        }),
-      ],
+    expect(result.diagnostics?.summary).toBe(
+      "cron payload.model 'anthropic/claude-sonnet-4-6' rejected: Model not allowed: anthropic/claude-sonnet-4-6",
+    );
+    expect(result.diagnostics?.entries).toHaveLength(1);
+    expect(result.diagnostics?.entries[0]?.ts).toBeTypeOf("number");
+    expect(result.diagnostics?.entries[0]).toEqual({
+      ts: result.diagnostics?.entries[0]?.ts,
+      source: "cron-preflight",
+      severity: "error",
+      message:
+        "cron payload.model 'anthropic/claude-sonnet-4-6' rejected: Model not allowed: anthropic/claude-sonnet-4-6",
     });
     // Model should remain undefined — the early return happens before the
     // pre-run persist block, so neither the session entry nor the store
@@ -240,7 +242,7 @@ describe("runCronIsolatedAgentTurn — cron model override (#21057)", () => {
     // The run should still complete successfully despite the persist failure
     expect(result.status).toBe("ok");
     expect(logWarnMock).toHaveBeenCalledWith(
-      expect.stringContaining("Failed to persist pre-run session entry"),
+      "[cron:digest-job] Failed to persist pre-run session entry: Error: ENOSPC: no space left on device",
     );
   });