diff --git a/src/pipecat/services/aws/nova_sonic/llm.py b/src/pipecat/services/aws/nova_sonic/llm.py
index 44e2b01a7..afd47a3fa 100644
--- a/src/pipecat/services/aws/nova_sonic/llm.py
+++ b/src/pipecat/services/aws/nova_sonic/llm.py
@@ -241,6 +241,17 @@ class AWSNovaSonicLLMService(LLMService[AWSNovaSonicLLMAdapter]):
 
     Provides bidirectional audio streaming, real-time transcription, text generation,
     and function calling capabilities using AWS Nova Sonic model.
+
+    Does NOT emit ``UserStartedSpeakingFrame`` / ``UserStoppedSpeakingFrame``,
+    so pipeline processors that depend on those frames — RTVI client
+    speech events, ``TurnTrackingObserver``, ``AudioBufferProcessor`` turn
+    recording, ``UserIdleController``, user mute strategies, voicemail
+    detector — won't activate with the default server-VAD-only setup. Pair
+    with ``LLMContextAggregatorPair(..., realtime_service_mode=RealtimeServiceModeConfig())``
+    so context writes are correct anyway. To produce the turn frames
+    locally, wire ``vad_analyzer=SileroVADAnalyzer()`` (or similar) into
+    ``LLMUserAggregatorParams``; locally-generated turn boundaries are a
+    heuristic and may not match Nova Sonic's server-side turn decisions.
     """
 
     Settings = AWSNovaSonicLLMSettings
diff --git a/src/pipecat/services/google/gemini_live/llm.py b/src/pipecat/services/google/gemini_live/llm.py
index 80d722d29..6d3c4fa0e 100644
--- a/src/pipecat/services/google/gemini_live/llm.py
+++ b/src/pipecat/services/google/gemini_live/llm.py
@@ -361,6 +361,18 @@ class GeminiLiveLLMService(LLMService[GeminiLLMAdapter]):
     This service enables real-time conversations with Gemini, supporting both
     text and audio modalities. It handles voice transcription, streaming audio
     responses, and tool usage.
+
+    Does NOT emit ``UserStartedSpeakingFrame`` / ``UserStoppedSpeakingFrame``
+    (the API exposes an ``interrupted`` event but no turn-start/-end), so
+    pipeline processors that depend on those frames — RTVI client speech
+    events, ``TurnTrackingObserver``, ``AudioBufferProcessor`` turn
+    recording, ``UserIdleController``, user mute strategies, voicemail
+    detector — won't activate with the default server-VAD-only setup. Pair
+    with ``LLMContextAggregatorPair(..., realtime_service_mode=RealtimeServiceModeConfig())``
+    so context writes are correct anyway. To produce the turn frames
+    locally, see ``examples/realtime/realtime-gemini-live-local-vad.py``;
+    note that locally-generated turn boundaries are a heuristic and may
+    not match Gemini Live's server-side turn decisions.
     """
 
     Settings = GeminiLiveLLMSettings
diff --git a/src/pipecat/services/inworld/realtime/llm.py b/src/pipecat/services/inworld/realtime/llm.py
index 352e669e4..c151ee2ee 100644
--- a/src/pipecat/services/inworld/realtime/llm.py
+++ b/src/pipecat/services/inworld/realtime/llm.py
@@ -201,6 +201,11 @@ class InworldRealtimeLLMService(LLMService[InworldRealtimeLLMAdapter]):
     Supports function calling, conversation management, and real-time
     transcription.
 
+    Emits ``UserStartedSpeakingFrame`` / ``UserStoppedSpeakingFrame`` from
+    Inworld's server-side VAD events. Pair with
+    ``LLMContextAggregatorPair(..., realtime_service_mode=RealtimeServiceModeConfig())``
+    so context writes are decoupled from those frames.
+
     Example::
 
         llm = InworldRealtimeLLMService(
diff --git a/src/pipecat/services/openai/realtime/llm.py b/src/pipecat/services/openai/realtime/llm.py
index 9ce78ab89..4ef98aa35 100644
--- a/src/pipecat/services/openai/realtime/llm.py
+++ b/src/pipecat/services/openai/realtime/llm.py
@@ -204,6 +204,15 @@ class OpenAIRealtimeLLMService(LLMService[OpenAIRealtimeLLMAdapter]):
     Implements the OpenAI Realtime API with WebSocket communication for low-latency
     bidirectional audio and text interactions. Supports function calling, conversation
     management, and real-time transcription.
+
+    Emits ``UserStartedSpeakingFrame`` / ``UserStoppedSpeakingFrame`` from
+    OpenAI's server-side VAD events, so pipeline processors that depend on
+    those frames (RTVI client speech events, ``TurnTrackingObserver``,
+    ``AudioBufferProcessor`` turn recording, ``UserIdleController``, user
+    mute strategies, voicemail detector) work out of the box. Pair with
+    ``LLMContextAggregatorPair(..., realtime_service_mode=RealtimeServiceModeConfig())``
+    so context writes are decoupled from those frames; see the
+    ``examples/realtime/realtime-openai.py`` example.
     """
 
     Settings = OpenAIRealtimeLLMSettings
diff --git a/src/pipecat/services/ultravox/llm.py b/src/pipecat/services/ultravox/llm.py
index d0f7b3a15..8cae4fbe5 100644
--- a/src/pipecat/services/ultravox/llm.py
+++ b/src/pipecat/services/ultravox/llm.py
@@ -174,6 +174,17 @@ class UltravoxRealtimeLLMService(LLMService):
 
     Note: Ultravox is an audio-native model, so voice transcriptions are not used
     by the model and may not always align with its understanding of user input.
+
+    Does NOT emit ``UserStartedSpeakingFrame`` / ``UserStoppedSpeakingFrame``,
+    so pipeline processors that depend on those frames — RTVI client
+    speech events, ``TurnTrackingObserver``, ``AudioBufferProcessor`` turn
+    recording, ``UserIdleController``, user mute strategies, voicemail
+    detector — won't activate with the default server-VAD-only setup. Pair
+    with ``LLMContextAggregatorPair(..., realtime_service_mode=RealtimeServiceModeConfig())``
+    so context writes are correct anyway. To produce the turn frames
+    locally, wire ``vad_analyzer=SileroVADAnalyzer()`` (or similar) into
+    ``LLMUserAggregatorParams``; locally-generated turn boundaries are a
+    heuristic and may not match Ultravox's server-side turn decisions.
     """
 
     Settings = UltravoxRealtimeLLMSettings
diff --git a/src/pipecat/services/xai/realtime/llm.py b/src/pipecat/services/xai/realtime/llm.py
index cbfdbaf61..0b9562fa9 100644
--- a/src/pipecat/services/xai/realtime/llm.py
+++ b/src/pipecat/services/xai/realtime/llm.py
@@ -195,6 +195,11 @@ class GrokRealtimeLLMService(LLMService[GrokRealtimeLLMAdapter]):
         - Built-in tools (web_search, x_search, file_search)
         - Custom function calling
         - Server-side VAD (Voice Activity Detection)
+
+    Emits ``UserStartedSpeakingFrame`` / ``UserStoppedSpeakingFrame`` from
+    Grok's server-side VAD events. Pair with
+    ``LLMContextAggregatorPair(..., realtime_service_mode=RealtimeServiceModeConfig())``
+    so context writes are decoupled from those frames.
     """
 
     Settings = GrokRealtimeLLMSettings