diff --git a/litellm/llms/anthropic/experimental_pass_through/adapters/transformation.py b/litellm/llms/anthropic/experimental_pass_through/adapters/transformation.py
index ed49943b7fe..133bc6b11e7 100644
--- a/litellm/llms/anthropic/experimental_pass_through/adapters/transformation.py
+++ b/litellm/llms/anthropic/experimental_pass_through/adapters/transformation.py
@@ -1418,7 +1418,7 @@ class LiteLLMAnthropicMessagesAdapter:
         for choice in choices:
             if choice.delta.content is not None and len(choice.delta.content) > 0:
                 text += choice.delta.content
-            if choice.delta.tool_calls is not None:
+            if choice.delta.tool_calls is not None and len(choice.delta.tool_calls) > 0:
                 partial_json = ""
                 for tool in choice.delta.tool_calls:
                     if (