diff --git a/tests/tracing/test_tracing.py b/tests/tracing/test_tracing.py
index 90f26400952b9..a492daf3b49ca 100644
--- a/tests/tracing/test_tracing.py
+++ b/tests/tracing/test_tracing.py
@@ -114,5 +114,5 @@ def test_traces(trace_service):
         SpanAttributes.LLM_LATENCY_TIME_TO_FIRST_TOKEN) == ttft
     e2e_time = metrics.finished_time - metrics.arrival_time
     assert attributes.get(SpanAttributes.LLM_LATENCY_E2E) == e2e_time
-    assert attributes.get(
-        SpanAttributes.LLM_LATENCY_TIME_IN_SCHEDULER) == metrics.scheduler_time
+    assert attributes.get(SpanAttributes.LLM_LATENCY_TIME_IN_SCHEDULER
+                          ) == metrics.scheduler_time
diff --git a/vllm/worker/worker_base.py b/vllm/worker/worker_base.py
index 85ab0d348e03d..e6ee14551fbd8 100644
--- a/vllm/worker/worker_base.py
+++ b/vllm/worker/worker_base.py
@@ -259,10 +259,9 @@ def _get_driver_input_and_broadcast(
     def prepare_input(
         self,
         execute_model_req: Optional[ExecuteModelRequest] = None
-    ) -> Optional[Tuple[ModelRunnerInputBase, WorkerInput]]:
-        """
-        Prepare the inputs to ModelRunner and workers.
-        """
+    ) -> Optional[List[SamplerOutput]]:
+        """Executes at least one model step on the given sequences, unless no
+        sequences are provided."""
         if self.is_driver_worker:
             if execute_model_req is None:
                 if self.do_metadata_broadcast: