diff --git a/homeassistant/components/conversation/chat_log.py b/homeassistant/components/conversation/chat_log.py
index 355f423dbb6..2de785dae7d 100644
--- a/homeassistant/components/conversation/chat_log.py
+++ b/homeassistant/components/conversation/chat_log.py
@@ -51,8 +51,7 @@ def async_get_chat_log(
             )
         if user_input is not None and (
             (content := chat_log.content[-1]).role != "user"
-            # MyPy doesn't understand that content is a UserContent here
-            or content.content != user_input.text  # type: ignore[union-attr]
+            or content.content != user_input.text
         ):
             chat_log.async_add_user_content(UserContent(content=user_input.text))
 
@@ -128,7 +127,7 @@ class ConverseError(HomeAssistantError):
 class SystemContent:
     """Base class for chat messages."""
 
-    role: str = field(init=False, default="system")
+    role: Literal["system"] = field(init=False, default="system")
     content: str
 
 
@@ -136,7 +135,7 @@ class SystemContent:
 class UserContent:
     """Assistant content."""
 
-    role: str = field(init=False, default="user")
+    role: Literal["user"] = field(init=False, default="user")
     content: str
 
 
@@ -144,7 +143,7 @@ class UserContent:
 class AssistantContent:
     """Assistant content."""
 
-    role: str = field(init=False, default="assistant")
+    role: Literal["assistant"] = field(init=False, default="assistant")
     agent_id: str
     content: str | None = None
     tool_calls: list[llm.ToolInput] | None = None
@@ -154,7 +153,7 @@ class AssistantContent:
 class ToolResultContent:
     """Tool result content."""
 
-    role: str = field(init=False, default="tool_result")
+    role: Literal["tool_result"] = field(init=False, default="tool_result")
     agent_id: str
     tool_call_id: str
     tool_name: str
@@ -193,8 +192,8 @@ class ChatLog:
 
         return (
             last_msg.role == "assistant"
-            and last_msg.content is not None  # type: ignore[union-attr]
-            and last_msg.content.strip().endswith(  # type: ignore[union-attr]
+            and last_msg.content is not None
+            and last_msg.content.strip().endswith(
                 (
                     "?",
                     ";",  # Greek question mark
diff --git a/homeassistant/components/google_generative_ai_conversation/conversation.py b/homeassistant/components/google_generative_ai_conversation/conversation.py
index 93546431391..4648f1afb4c 100644
--- a/homeassistant/components/google_generative_ai_conversation/conversation.py
+++ b/homeassistant/components/google_generative_ai_conversation/conversation.py
@@ -188,7 +188,7 @@ def _convert_content(
     | conversation.SystemContent,
 ) -> Content:
     """Convert HA content to Google content."""
-    if content.role != "assistant" or not content.tool_calls:  # type: ignore[union-attr]
+    if content.role != "assistant" or not content.tool_calls:
         role = "model" if content.role == "assistant" else content.role
         return Content(
             role=role,
@@ -321,24 +321,14 @@ class GoogleGenerativeAIConversationEntity(
 
         for chat_content in chat_log.content[1:-1]:
             if chat_content.role == "tool_result":
-                # mypy doesn't like picking a type based on checking shared property 'role'
-                tool_results.append(cast(conversation.ToolResultContent, chat_content))
+                tool_results.append(chat_content)
                 continue
 
             if tool_results:
                 messages.append(_create_google_tool_response_content(tool_results))
                 tool_results.clear()
 
-            messages.append(
-                _convert_content(
-                    cast(
-                        conversation.UserContent
-                        | conversation.SystemContent
-                        | conversation.AssistantContent,
-                        chat_content,
-                    )
-                )
-            )
+            messages.append(_convert_content(chat_content))
 
         if tool_results:
             messages.append(_create_google_tool_response_content(tool_results))
diff --git a/homeassistant/components/openai_conversation/conversation.py b/homeassistant/components/openai_conversation/conversation.py
index e42319f8e96..d910cf54471 100644
--- a/homeassistant/components/openai_conversation/conversation.py
+++ b/homeassistant/components/openai_conversation/conversation.py
@@ -82,13 +82,13 @@ def _convert_content_to_param(
             tool_call_id=content.tool_call_id,
             content=json.dumps(content.tool_result),
         )
-    if content.role != "assistant" or not content.tool_calls:  # type: ignore[union-attr]
-        role = content.role
+    if content.role != "assistant" or not content.tool_calls:
+        role: Literal["system", "user", "assistant", "developer"] = content.role
         if role == "system":
             role = "developer"
         return cast(
             ChatCompletionMessageParam,
-            {"role": content.role, "content": content.content},  # type: ignore[union-attr]
+            {"role": content.role, "content": content.content},
         )
 
     # Handle the Assistant content including tool calls.