diff --git a/src/google/adk/agents/active_streaming_tool.py b/src/google/adk/agents/active_streaming_tool.py
index e5499e0..db0a764 100644
--- a/src/google/adk/agents/active_streaming_tool.py
+++ b/src/google/adk/agents/active_streaming_tool.py
@@ -30,6 +30,7 @@ class ActiveStreamingTool(BaseModel):
       arbitrary_types_allowed=True,
       extra='forbid',
   )
+  """The pydantic model config."""
 
   task: Optional[asyncio.Task] = None
   """The active task of this streaming tool."""
diff --git a/src/google/adk/agents/base_agent.py b/src/google/adk/agents/base_agent.py
index 764fedb..067e1aa 100644
--- a/src/google/adk/agents/base_agent.py
+++ b/src/google/adk/agents/base_agent.py
@@ -50,6 +50,7 @@ class BaseAgent(BaseModel):
       arbitrary_types_allowed=True,
       extra='forbid',
   )
+  """The pydantic model config."""
 
   name: str
   """The agent's name.
diff --git a/src/google/adk/agents/invocation_context.py b/src/google/adk/agents/invocation_context.py
index 9acee44..46ec663 100644
--- a/src/google/adk/agents/invocation_context.py
+++ b/src/google/adk/agents/invocation_context.py
@@ -110,6 +110,7 @@ class InvocationContext(BaseModel):
       arbitrary_types_allowed=True,
       extra="forbid",
   )
+  """The pydantic model config."""
 
   artifact_service: Optional[BaseArtifactService] = None
   session_service: BaseSessionService
diff --git a/src/google/adk/agents/langgraph_agent.py b/src/google/adk/agents/langgraph_agent.py
index 33a21b4..f07b203 100644
--- a/src/google/adk/agents/langgraph_agent.py
+++ b/src/google/adk/agents/langgraph_agent.py
@@ -53,6 +53,7 @@ class LangGraphAgent(BaseAgent):
   model_config = ConfigDict(
       arbitrary_types_allowed=True,
   )
+  """The pydantic model config."""
 
   graph: CompiledGraph
 
diff --git a/src/google/adk/agents/live_request_queue.py b/src/google/adk/agents/live_request_queue.py
index 3caf725..837750e 100644
--- a/src/google/adk/agents/live_request_queue.py
+++ b/src/google/adk/agents/live_request_queue.py
@@ -24,6 +24,7 @@ class LiveRequest(BaseModel):
   """Request send to live agents."""
 
   model_config = ConfigDict(ser_json_bytes='base64', val_json_bytes='base64')
+  """The pydantic model config."""
 
   content: Optional[types.Content] = None
   """If set, send the content to the model in turn-by-turn mode."""
diff --git a/src/google/adk/agents/run_config.py b/src/google/adk/agents/run_config.py
index 17dff29..e121750 100644
--- a/src/google/adk/agents/run_config.py
+++ b/src/google/adk/agents/run_config.py
@@ -37,6 +37,7 @@ class RunConfig(BaseModel):
   model_config = ConfigDict(
       extra='forbid',
   )
+  """The pydantic model config."""
 
   speech_config: Optional[types.SpeechConfig] = None
   """Speech configuration for the live agent."""
diff --git a/src/google/adk/agents/transcription_entry.py b/src/google/adk/agents/transcription_entry.py
index f415e7c..c59ad88 100644
--- a/src/google/adk/agents/transcription_entry.py
+++ b/src/google/adk/agents/transcription_entry.py
@@ -26,6 +26,7 @@ class TranscriptionEntry(BaseModel):
       arbitrary_types_allowed=True,
       extra='forbid',
   )
+  """The pydantic model config."""
 
   role: str
   """The role that created this data, typically "user" or "model"""
diff --git a/src/google/adk/auth/auth_credential.py b/src/google/adk/auth/auth_credential.py
index 90fbbee..ed2ec48 100644
--- a/src/google/adk/auth/auth_credential.py
+++ b/src/google/adk/auth/auth_credential.py
@@ -13,17 +13,16 @@
 # limitations under the License.
 
 from enum import Enum
-from typing import Any
-from typing import Dict
-from typing import List
-from typing import Optional
+from typing import Any, Dict, List, Optional
 
 from pydantic import BaseModel
+from pydantic import ConfigDict
 from pydantic import Field
 
 
 class BaseModelWithConfig(BaseModel):
-  model_config = {"extra": "allow"}
+  model_config = ConfigDict(extra="allow")
+  """The pydantic model config."""
 
 
 class HttpCredentials(BaseModelWithConfig):
diff --git a/src/google/adk/events/event.py b/src/google/adk/events/event.py
index c2ff07d..c36f6fc 100644
--- a/src/google/adk/events/event.py
+++ b/src/google/adk/events/event.py
@@ -48,6 +48,7 @@ class Event(LlmResponse):
   model_config = ConfigDict(
       extra='forbid', ser_json_bytes='base64', val_json_bytes='base64'
   )
+  """The pydantic model config."""
 
   # TODO: revert to be required after spark migration
   invocation_id: str = ''
diff --git a/src/google/adk/events/event_actions.py b/src/google/adk/events/event_actions.py
index f4f4078..6597edb 100644
--- a/src/google/adk/events/event_actions.py
+++ b/src/google/adk/events/event_actions.py
@@ -27,6 +27,7 @@ class EventActions(BaseModel):
   """Represents the actions attached to an event."""
 
   model_config = ConfigDict(extra='forbid')
+  """The pydantic model config."""
 
   skip_summarization: Optional[bool] = None
   """If true, it won't call model to summarize function response.
diff --git a/src/google/adk/models/base_llm.py b/src/google/adk/models/base_llm.py
index b605829..6d71cf9 100644
--- a/src/google/adk/models/base_llm.py
+++ b/src/google/adk/models/base_llm.py
@@ -14,11 +14,9 @@
 from __future__ import annotations
 
 from abc import abstractmethod
-from typing import AsyncGenerator
-from typing import TYPE_CHECKING
+from typing import AsyncGenerator, TYPE_CHECKING
 
 from google.genai import types
-
 from pydantic import BaseModel
 from pydantic import ConfigDict
 
@@ -34,14 +32,13 @@ class BaseLlm(BaseModel):
 
   Attributes:
     model: The name of the LLM, e.g. gemini-1.5-flash or gemini-1.5-flash-001.
-    model_config: The model config
   """
 
   model_config = ConfigDict(
       # This allows us to use arbitrary types in the model. E.g. PIL.Image.
       arbitrary_types_allowed=True,
   )
-  """The model config."""
+  """The pydantic model config."""
 
   model: str
   """The name of the LLM, e.g. gemini-1.5-flash or gemini-1.5-flash-001."""
diff --git a/src/google/adk/models/lite_llm.py b/src/google/adk/models/lite_llm.py
index cc4184f..70e22a9 100644
--- a/src/google/adk/models/lite_llm.py
+++ b/src/google/adk/models/lite_llm.py
@@ -573,7 +573,6 @@ class LiteLlm(BaseLlm):
   Attributes:
     model: The name of the LiteLlm model.
     llm_client: The LLM client to use for the model.
-    model_config: The model config.
   """
 
   llm_client: LiteLLMClient = Field(default_factory=LiteLLMClient)
diff --git a/src/google/adk/models/llm_request.py b/src/google/adk/models/llm_request.py
index cc97c55..dcb616b 100644
--- a/src/google/adk/models/llm_request.py
+++ b/src/google/adk/models/llm_request.py
@@ -37,7 +37,7 @@ class LlmRequest(BaseModel):
   """
 
   model_config = ConfigDict(arbitrary_types_allowed=True)
-  """The model config."""
+  """The pydantic model config."""
 
   model: Optional[str] = None
   """The model name."""
diff --git a/src/google/adk/models/llm_response.py b/src/google/adk/models/llm_response.py
index d7a613d..353af5d 100644
--- a/src/google/adk/models/llm_response.py
+++ b/src/google/adk/models/llm_response.py
@@ -41,7 +41,7 @@ class LlmResponse(BaseModel):
   """
 
   model_config = ConfigDict(extra='forbid')
-  """The model config."""
+  """The pydantic model config."""
 
   content: Optional[types.Content] = None
   """The content of the response."""
diff --git a/src/google/adk/sessions/session.py b/src/google/adk/sessions/session.py
index 3d3fac5..f457ce7 100644
--- a/src/google/adk/sessions/session.py
+++ b/src/google/adk/sessions/session.py
@@ -38,6 +38,7 @@ class Session(BaseModel):
       extra='forbid',
       arbitrary_types_allowed=True,
   )
+  """The pydantic model config."""
 
   id: str
   """The unique identifier of the session."""