diff --git a/src/lmstudio/history.py b/src/lmstudio/history.py
index 4e62452..548371d 100644
--- a/src/lmstudio/history.py
+++ b/src/lmstudio/history.py
@@ -135,9 +135,13 @@ def _to_history_content(self) -> str:
     | ToolCallRequestData
     | ToolCallRequestDataDict
 )
+AssistantMultiPartInput = Iterable[AssistantResponseInput | ToolCallRequestInput]
 ToolCallResultInput = ToolCallResultData | ToolCallResultDataDict
+ToolCallResultMultiPartInput = Iterable[ToolCallResultInput]
 ChatMessageInput = str | ChatMessageContent | ChatMessageContentDict
-ChatMessageMultiPartInput = UserMessageMultiPartInput
+ChatMessageMultiPartInput = (
+    UserMessageMultiPartInput | AssistantMultiPartInput | ToolCallResultMultiPartInput
+)
 AnyChatMessageInput = ChatMessageInput | ChatMessageMultiPartInput
 
 
@@ -251,9 +255,12 @@ def add_entry(self, role: str, content: AnyChatMessageInput) -> AnyChatMessage:
         if role == "user":
             messages = cast(AnyUserMessageInput, content)
             return self.add_user_message(messages)
+        # Tool results accept multi-part content, so just forward it to that method
+        if role == "tool":
+            tool_results = cast(Iterable[ToolCallResultInput], content)
+            return self.add_tool_results(tool_results)
         # Assistant responses consist of a text response with zero or more tool requests
         if role == "assistant":
-            response: AssistantResponseInput
             if _is_chat_message_input(content):
                 response = cast(AssistantResponseInput, content)
                 return self.add_assistant_response(response)
@@ -263,7 +270,7 @@ def add_entry(self, role: str, content: AnyChatMessageInput) -> AnyChatMessage:
                 raise LMStudioValueError(
                     f"Unable to parse assistant response content: {content}"
                 ) from None
-            response = response_content
+            response = cast(AssistantResponseInput, response_content)
             tool_requests = cast(Iterable[ToolCallRequest], tool_request_contents)
             return self.add_assistant_response(response, tool_requests)
 
@@ -276,7 +283,7 @@ def add_entry(self, role: str, content: AnyChatMessageInput) -> AnyChatMessage:
             content_item = content
         else:
             try:
-                (content_item,) = content
+                (content_item,) = cast(Iterable[ChatMessageInput], content)
             except ValueError:
                 err_msg = f"{role!r} role does not support multi-part message content."
                 raise LMStudioValueError(err_msg) from None
@@ -284,9 +291,6 @@ def add_entry(self, role: str, content: AnyChatMessageInput) -> AnyChatMessage:
             case "system":
                 prompt = cast(SystemPromptInput, content_item)
                 result = self.add_system_prompt(prompt)
-            case "tool":
-                tool_result = cast(ToolCallResultInput, content_item)
-                result = self.add_tool_result(tool_result)
             case _:
                 raise LMStudioValueError(f"Unknown history role: {role}")
         return result
diff --git a/tests/test_history.py b/tests/test_history.py
index 6ec7925..ce20483 100644
--- a/tests/test_history.py
+++ b/tests/test_history.py
@@ -10,9 +10,10 @@
 from lmstudio.sdk_api import LMStudioOSError
 from lmstudio.schemas import DictObject
 from lmstudio.history import (
+    AnyChatMessageDict,
     AnyChatMessageInput,
+    AssistantMultiPartInput,
     Chat,
-    AnyChatMessageDict,
     ChatHistoryData,
     ChatHistoryDataDict,
     LocalFileInput,
@@ -29,6 +30,10 @@
     LlmPredictionStats,
     PredictionResult,
 )
+from lmstudio._sdk_models import (
+    ToolCallRequestDataDict,
+    ToolCallResultDataDict,
+)
 
 from .support import IMAGE_FILEPATH, check_sdk_error
 
@@ -125,6 +130,51 @@
         "role": "system",
         "content": [{"type": "text", "text": "Structured text system prompt"}],
     },
+    {
+        "role": "assistant",
+        "content": [
+            {"type": "text", "text": "Example tool call request"},
+            {
+                "type": "toolCallRequest",
+                "toolCallRequest": {
+                    "type": "function",
+                    "id": "114663647",
+                    "name": "example_tool_name",
+                    "arguments": {
+                        "n": 58013,
+                        "t": "value",
+                    },
+                },
+            },
+            {
+                "type": "toolCallRequest",
+                "toolCallRequest": {
+                    "type": "function",
+                    "id": "114663648",
+                    "name": "another_example_tool_name",
+                    "arguments": {
+                        "n": 23,
+                        "t": "some other value",
+                    },
+                },
+            },
+        ],
+    },
+    {
+        "role": "tool",
+        "content": [
+            {
+                "type": "toolCallResult",
+                "toolCallId": "114663647",
+                "content": "example tool call result",
+            },
+            {
+                "type": "toolCallResult",
+                "toolCallId": "114663648",
+                "content": "another example tool call result",
+            },
+        ],
+    },
 ]
 
 INPUT_HISTORY = {"messages": INPUT_ENTRIES}
@@ -214,6 +264,51 @@
         "role": "system",
         "content": [{"type": "text", "text": "Structured text system prompt"}],
     },
+    {
+        "role": "assistant",
+        "content": [
+            {"type": "text", "text": "Example tool call request"},
+            {
+                "type": "toolCallRequest",
+                "toolCallRequest": {
+                    "type": "function",
+                    "id": "114663647",
+                    "name": "example_tool_name",
+                    "arguments": {
+                        "n": 58013,
+                        "t": "value",
+                    },
+                },
+            },
+            {
+                "type": "toolCallRequest",
+                "toolCallRequest": {
+                    "type": "function",
+                    "id": "114663648",
+                    "name": "another_example_tool_name",
+                    "arguments": {
+                        "n": 23,
+                        "t": "some other value",
+                    },
+                },
+            },
+        ],
+    },
+    {
+        "role": "tool",
+        "content": [
+            {
+                "type": "toolCallResult",
+                "toolCallId": "114663647",
+                "content": "example tool call result",
+            },
+            {
+                "type": "toolCallResult",
+                "toolCallId": "114663648",
+                "content": "another example tool call result",
+            },
+        ],
+    },
 ]
 
 
@@ -271,6 +366,44 @@ def test_from_history_with_simple_text() -> None:
     "sizeBytes": 100,
     "fileType": "text/plain",
 }
+INPUT_TOOL_REQUESTS: list[ToolCallRequestDataDict] = [
+    {
+        "type": "toolCallRequest",
+        "toolCallRequest": {
+            "type": "function",
+            "id": "114663647",
+            "name": "example_tool_name",
+            "arguments": {
+                "n": 58013,
+                "t": "value",
+            },
+        },
+    },
+    {
+        "type": "toolCallRequest",
+        "toolCallRequest": {
+            "type": "function",
+            "id": "114663648",
+            "name": "another_example_tool_name",
+            "arguments": {
+                "n": 23,
+                "t": "some other value",
+            },
+        },
+    },
+]
+INPUT_TOOL_RESULTS: list[ToolCallResultDataDict] = [
+    {
+        "type": "toolCallResult",
+        "toolCallId": "114663647",
+        "content": "example tool call result",
+    },
+    {
+        "type": "toolCallResult",
+        "toolCallId": "114663648",
+        "content": "another example tool call result",
+    },
+]
 
 
 def test_get_history() -> None:
@@ -289,6 +422,8 @@ def test_get_history() -> None:
     chat.add_user_message("Avoid consecutive responses")
     chat.add_assistant_response(INPUT_FILE_HANDLE_DICT)
     chat.add_system_prompt(TextData(text="Structured text system prompt"))
+    chat.add_assistant_response("Example tool call request", INPUT_TOOL_REQUESTS)
+    chat.add_tool_results(INPUT_TOOL_RESULTS)
     assert chat._get_history_for_prediction() == EXPECTED_HISTORY
 
 
@@ -307,6 +442,19 @@ def test_add_entry() -> None:
     chat.add_entry("user", "Avoid consecutive responses")
     chat.add_entry("assistant", INPUT_FILE_HANDLE_DICT)
     chat.add_entry("system", TextData(text="Structured text system prompt"))
+    tool_call_message_contents: AssistantMultiPartInput = [
+        "Example tool call request",
+        *INPUT_TOOL_REQUESTS,
+    ]
+    chat.add_entry("assistant", tool_call_message_contents)
+    chat.add_entry("tool", INPUT_TOOL_RESULTS)
+    assert chat._get_history_for_prediction() == EXPECTED_HISTORY
+
+
+def test_append() -> None:
+    chat = Chat()
+    for message in INPUT_ENTRIES:
+        chat.append(cast(AnyChatMessageDict, message))
     assert chat._get_history_for_prediction() == EXPECTED_HISTORY