Python: fix(ollama): send the tool name on tool result messages

python/packages/ollama/agent_framework_ollama/_chat_client.py

@@ -6,6 +6,7 @@
 import logging
 import sys
 import uuid
+from collections import deque
 from collections.abc import (
     AsyncIterable,
     Awaitable,
@@ -459,7 +460,19 @@ def _prepare_options(self, messages: Sequence[Message], options: Mapping[str, An
         return run_options
 
     def _prepare_messages_for_ollama(self, messages: Sequence[Message]) -> list[OllamaMessage]:
-        ollama_messages = [self._prepare_message_for_ollama(msg) for msg in messages]
+        # Function results don't carry the tool name, but Ollama expects it on tool messages.
+        # Walk the messages in order and give each result the name of the earliest unanswered
+        # call with the same call_id, so a call_id reused later still maps correctly.
+        pending_calls: dict[str, deque[str]] = {}
+        ollama_messages: list[list[OllamaMessage]] = []
+        for msg in messages:
+            if msg.role == "tool":
+                ollama_messages.append(self._format_tool_message(msg, pending_calls))
+                continue
+            for content in msg.contents:
+                if content.type == "function_call" and content.call_id and content.name:
+                    pending_calls.setdefault(content.call_id, deque()).append(content.name)
+            ollama_messages.append(self._prepare_message_for_ollama(msg))
         # Flatten the list of lists into a single list
         return list(chain.from_iterable(ollama_messages))
 
@@ -518,7 +531,9 @@ def _format_assistant_message(self, message: Message) -> list[OllamaMessage]:
             ]
         return [assistant_message]
 
-    def _format_tool_message(self, message: Message) -> list[OllamaMessage]:
+    def _format_tool_message(
+        self, message: Message, pending_calls: dict[str, deque[str]] | None = None
+    ) -> list[OllamaMessage]:
         # Ollama does not support multiple tool results in a single message, so we create a separate
         messages: list[OllamaMessage] = []
         for item in message.contents:
@@ -535,8 +550,11 @@ def _format_tool_message(self, message: Message) -> list[OllamaMessage]:
                 else:
                     tool_text = str(item.result) if item.result is not None else ""
 
-                # Get the tool name directly from the content item.
-                tool_name = getattr(item, "name", "") or ""
+                tool_name = getattr(item, "name", None) or ""
+                pending = (pending_calls or {}).get(item.call_id or "")
+                if pending:
+                    queued_name = pending.popleft()
+                    tool_name = tool_name or queued_name
                 messages.append(OllamaMessage(role="tool", content=tool_text, tool_name=tool_name))
         return messages
 

python/packages/ollama/tests/test_ollama_chat_client.py

@@ -829,6 +829,49 @@ def test_mixed_policy_approval_roles_preserve_tool_result(self) -> None:
         assert [message.role for message in prepared] == ["tool", "assistant"]
         assert prepared[0].content == "safe result"
 
+    def test_tool_message_gets_name_from_matching_function_call(self) -> None:
+        """Function results carry no name, so the tool name comes from the call with the same call_id."""
+        client = OllamaChatClient(host="http://localhost:12345", model="test-model")
+        messages = [
+            Message(role="user", contents=[Content.from_text("weather in Paris and Oslo?")]),
+            Message(
+                role="assistant",
+                contents=[
+                    Content.from_function_call(call_id="c1", name="get_weather", arguments={"city": "Paris"}),
+                    Content.from_function_call(call_id="c2", name="get_time", arguments={"city": "Oslo"}),
+                ],
+            ),
+            Message(
+                role="tool",
+                contents=[
+                    Content.from_function_result(call_id="c2", result="10:00"),
+                    Content.from_function_result(call_id="c1", result="sunny"),
+                ],
+            ),
+        ]
+
+        prepared = client._prepare_messages_for_ollama(messages)
+
+        tool_messages = [message for message in prepared if message.role == "tool"]
+        assert [(m.content, m.tool_name) for m in tool_messages] == [("10:00", "get_time"), ("sunny", "get_weather")]
+
+    def test_tool_message_name_with_reused_call_id(self) -> None:
+        """A call_id reused later in the transcript maps each result to its own call."""
+        client = OllamaChatClient(host="http://localhost:12345", model="test-model")
+        messages = [
+            Message(role="user", contents=[Content.from_text("weather?")]),
+            Message(role="assistant", contents=[Content.from_function_call(call_id="c1", name="get_weather")]),
+            Message(role="tool", contents=[Content.from_function_result(call_id="c1", result="sunny")]),
+            Message(role="user", contents=[Content.from_text("time?")]),
+            Message(role="assistant", contents=[Content.from_function_call(call_id="c1", name="get_time")]),
+            Message(role="tool", contents=[Content.from_function_result(call_id="c1", result="10:00")]),
+        ]
+
+        prepared = client._prepare_messages_for_ollama(messages)
+
+        tool_messages = [message for message in prepared if message.role == "tool"]
+        assert [(m.content, m.tool_name) for m in tool_messages] == [("sunny", "get_weather"), ("10:00", "get_time")]
+
 
 def test_prepare_options_single_stop_string_becomes_list(ollama_unit_test_env: dict[str, str]) -> None:
     """Ollama expects options.stop to be a list, so a single stop string is wrapped."""