diff --git a/core/src/commonMain/kotlin/com/xebia/functional/xef/llm/assistants/AssistantThread.kt b/core/src/commonMain/kotlin/com/xebia/functional/xef/llm/assistants/AssistantThread.kt
index 019c8911f..dc0402b30 100644
--- a/core/src/commonMain/kotlin/com/xebia/functional/xef/llm/assistants/AssistantThread.kt
+++ b/core/src/commonMain/kotlin/com/xebia/functional/xef/llm/assistants/AssistantThread.kt
@@ -134,7 +134,7 @@ class AssistantThread(
         emit(RunDelta.Step(step))
         step.stepDetails.toolCalls().forEach { toolCall ->
           val function = toolCall.function
-          if (function != null) {
+          if (function != null && function.arguments.isNotBlank()) {
             val result: JsonElement = Tool(function.name, function.arguments)
             api.submitToolOuputsToRun(
               threadId = threadId,