diff --git a/litellm/llms/oci/chat/cohere.py b/litellm/llms/oci/chat/cohere.py
index 39caebba03a..441c67d59d1 100644
--- a/litellm/llms/oci/chat/cohere.py
+++ b/litellm/llms/oci/chat/cohere.py
@@ -60,7 +60,11 @@ def adapt_messages_to_cohere_standard(
 ) -> List[CohereMessage]:
     """Build a Cohere ``chatHistory`` list from an OpenAI-format message array.
 
-    - All messages except the last are included (the last becomes ``message``).
+    - All messages except the *last user message* are included. The caller pulls
+      the last user message into the request's top-level ``message`` field, so
+      trailing tool results (the standard agentic continuation pattern) still
+      appear in ``chatHistory`` and reach the model.
+    - If no user message exists, every message is included (no slice).
     - Tool results are expressed as OCI ``CohereToolMessage.toolResults`` entries,
       with the originating call's name and parameters resolved from the preceding
       assistant message via a ``tool_call_id`` lookup.
@@ -85,8 +89,22 @@ def adapt_messages_to_cohere_standard(
                     parameters=params,
                 )
 
+    last_user_index = next(
+        (
+            i
+            for i in range(len(messages) - 1, -1, -1)
+            if messages[i].get("role") == "user"
+        ),
+        None,
+    )
+    history_source = (
+        messages
+        if last_user_index is None
+        else [m for i, m in enumerate(messages) if i != last_user_index]
+    )
+
     chat_history: List[CohereMessage] = []
-    for msg in messages[:-1]:
+    for msg in history_source:
         role = msg.get("role")
         content = _extract_text_content(msg.get("content"))
 
diff --git a/tests/test_litellm/llms/oci/chat/test_oci_cohere_tool_calls.py b/tests/test_litellm/llms/oci/chat/test_oci_cohere_tool_calls.py
index 4414d1ddd10..3ae64c03240 100644
--- a/tests/test_litellm/llms/oci/chat/test_oci_cohere_tool_calls.py
+++ b/tests/test_litellm/llms/oci/chat/test_oci_cohere_tool_calls.py
@@ -326,20 +326,24 @@ class TestOCICohereToolCalls:
 
         chat_history = adapt_messages_to_cohere_standard(messages)
 
-        # First message is the user message
-        assert chat_history[0].role == "USER"
-        assert chat_history[0].message == "What's the weather?"
+        # The last user message is consumed by the request's top-level `message`
+        # field, so chatHistory carries the assistant tool call and tool result.
+        assert len(chat_history) == 2
 
-        # Second message is the assistant with tool calls and no text
-        assistant_msg = chat_history[1]
+        assistant_msg = chat_history[0]
         assert assistant_msg.role == "CHATBOT"
         assert assistant_msg.message is None or assistant_msg.message == ""
         assert assistant_msg.toolCalls is not None
         assert len(assistant_msg.toolCalls) == 1
         assert assistant_msg.toolCalls[0].name == "get_weather"
 
+        tool_msg = chat_history[1]
+        assert tool_msg.role == "TOOL"
+        assert tool_msg.toolResults[0].call.name == "get_weather"
+        assert tool_msg.toolResults[0].outputs[0]["output"] == "Sunny, 25C"
+
     def test_cohere_chat_history_with_tool_calls(self):
-        """Test chat history transformation with tool calls"""
+        """Tool results trailing the last user turn must be preserved in chatHistory."""
         config = OCIChatConfig()
 
         messages = [
@@ -367,26 +371,27 @@ class TestOCICohereToolCalls:
 
         chat_history = adapt_messages_to_cohere_standard(messages)
 
-        # Verify chat history structure (excludes last message)
+        # The last user message becomes the request's top-level `message`.
+        # Everything else — including the trailing tool result — must remain in
+        # chatHistory so the model can see the tool output.
         assert len(chat_history) == 2
 
-        # Check user message
-        user_msg = chat_history[0]
-        assert user_msg.role == "USER"
-        assert user_msg.message == "What's the weather like in Tokyo?"
-
-        # Check assistant message with tool calls
-        assistant_msg = chat_history[1]
+        assistant_msg = chat_history[0]
         assert assistant_msg.role == "CHATBOT"
         assert assistant_msg.message == "I will look up the weather in Tokyo."
         assert assistant_msg.toolCalls is not None
         assert len(assistant_msg.toolCalls) == 1
         assert assistant_msg.toolCalls[0].name == "get_weather"
-        # The parameters should be parsed as JSON
         assert assistant_msg.toolCalls[0].parameters == {"location": "Tokyo"}
 
-        # Note: The tool message (last message) is excluded from chat history
-        # This is the expected behavior for Cohere models
+        tool_msg = chat_history[1]
+        assert tool_msg.role == "TOOL"
+        assert tool_msg.toolResults[0].call.name == "get_weather"
+        assert tool_msg.toolResults[0].call.parameters == {"location": "Tokyo"}
+        assert (
+            tool_msg.toolResults[0].outputs[0]["output"]
+            == "The weather in Tokyo is 22°C with partly cloudy skies."
+        )
 
     def test_cohere_streaming_chunk_handling(self):
         """Test Cohere streaming chunk handling"""