fix: ollama input/output token count (#2008)

Author: lizradway

src/strands/models/ollama.py

@@ -273,8 +273,8 @@ def format_chunk(self, event: dict[str, Any]) -> StreamEvent:
                 return {
                     "metadata": {
                         "usage": {
-                            "inputTokens": event["data"].eval_count,
-                            "outputTokens": event["data"].prompt_eval_count,
+                            "inputTokens": event["data"].prompt_eval_count,
+                            "outputTokens": event["data"].eval_count,
                             "totalTokens": event["data"].eval_count + event["data"].prompt_eval_count,
                         },
                         "metrics": {

tests/strands/models/test_ollama.py

@@ -394,8 +394,8 @@ def test_format_chunk_metadata(model):
     exp_chunk = {
         "metadata": {
             "usage": {
-                "inputTokens": 100,
-                "outputTokens": 50,
+                "inputTokens": 50,
+                "outputTokens": 100,
                 "totalTokens": 150,
             },
             "metrics": {
@@ -438,7 +438,7 @@ async def test_stream(ollama_client, model, agenerator, alist, captured_warnings
         {"messageStop": {"stopReason": "end_turn"}},
         {
             "metadata": {
-                "usage": {"inputTokens": 10, "outputTokens": 5, "totalTokens": 15},
+                "usage": {"inputTokens": 5, "outputTokens": 10, "totalTokens": 15},
                 "metrics": {"latencyMs": 1.0},
             }
         },
@@ -510,7 +510,7 @@ async def test_stream_with_tool_calls(ollama_client, model, agenerator, alist):
         {"messageStop": {"stopReason": "tool_use"}},
         {
             "metadata": {
-                "usage": {"inputTokens": 15, "outputTokens": 8, "totalTokens": 23},
+                "usage": {"inputTokens": 8, "outputTokens": 15, "totalTokens": 23},
                 "metrics": {"latencyMs": 2.0},
             }
         },