From ae79d982509b8b12e9cb2afd77cacc13a4a2869b Mon Sep 17 00:00:00 2001
From: Baojiang Lee <101562714+libaojiang@users.noreply.github.com>
Date: Mon, 31 Aug 2026 10:19:26 +0800
Subject: [PATCH] style(vertex_ai): remove redundant signature comments

---
 .../litellm_core_utils/prompt_templates/factory.py   |  7 +------
 .../gemini/test_thought_signature_in_tool_call_id.py | 12 ------------
 2 files changed, 1 insertion(+), 18 deletions(-)

diff --git a/litellm/litellm_core_utils/prompt_templates/factory.py b/litellm/litellm_core_utils/prompt_templates/factory.py
index 2714c0f29c5..5f3568c64c2 100644
--- a/litellm/litellm_core_utils/prompt_templates/factory.py
+++ b/litellm/litellm_core_utils/prompt_templates/factory.py
@@ -1212,12 +1212,7 @@ def _get_thought_signature_from_tool(tool: dict) -> str | None:
                 signature = function.provider_specific_fields.get("thought_signature")
                 if signature:
                     return signature
-    # Check if thought signature is embedded in tool call ID.
-    # Any client that normalizes the id shortens/hashes it, so the segment
-    # after ``__thought__`` may no longer base64-decode. Reject those here so
-    # the caller can decide between "no signature" and the dummy fallback,
-    # instead of forwarding a corrupted value that would 400 on Vertex. See
-    # issue #37849.
+    # Check if thought signature is embedded in tool call ID
     tool_call_id: Final = tool.get("id")
     if tool_call_id and THOUGHT_SIGNATURE_SEPARATOR in tool_call_id:
         parts: Final = tool_call_id.split(THOUGHT_SIGNATURE_SEPARATOR, 1)
diff --git a/tests/test_litellm/llms/vertex_ai/gemini/test_thought_signature_in_tool_call_id.py b/tests/test_litellm/llms/vertex_ai/gemini/test_thought_signature_in_tool_call_id.py
index ef1002c8399..489564c3e0c 100644
--- a/tests/test_litellm/llms/vertex_ai/gemini/test_thought_signature_in_tool_call_id.py
+++ b/tests/test_litellm/llms/vertex_ai/gemini/test_thought_signature_in_tool_call_id.py
@@ -246,9 +246,6 @@ def test_openai_client_e2e_flow(enable_preview_features):
 @pytest.mark.parametrize("enable_preview_features", [True, False])
 def test_parallel_tool_calls_with_signatures(enable_preview_features):
     """Test that parallel tool calls preserve signatures correctly"""
-    # Real Gemini signatures are standard-alphabet base64; using a valid
-    # placeholder keeps the parallel-tool-call path lit up under the
-    # base64-validated extraction added for issue #37849.
     signature1 = base64.b64encode(b"signature_for_first_call").decode("ascii")
     # Only first call has signature (Gemini behavior for parallel calls)
 
@@ -294,18 +291,11 @@ REAL_SIGNATURE = (
 )
 
 
-# Signature values a client-side id sanitizer produces after stripping the raw
-# base64 down to id-shaped characters. Standard-alphabet base64 has no ``_`` or
-# trailing hex fragment, so Vertex rejects these with either "Base64 decoding
-# failed" or "Invalid thought signature". See issue #37849.
 @pytest.mark.parametrize(
     "mangled_signature",
     [
-        # from the issue reproducer, /v1/responses turn 2
         "AY89a1/_57b05e78dc",
-        # from the issue reproducer, /v1/chat/completions turn 2
         "AY89a1/_ee781c9832",
-        # short SHA-suffix-only sanitization
         "AY89a1_S3YvIpUCcBTFSgDfesRLDnA_775ff49bcd",
     ],
 )
@@ -315,8 +305,6 @@ def test_is_valid_thought_signature_rejects_client_normalized_values(mangled_sig
 
 
 def test_is_valid_thought_signature_tolerates_missing_padding():
-    # Gemini omits ``=`` on the wire; the strict decoder must still accept the
-    # value once we re-pad it.
     encoded = base64.b64encode(b"hello").decode("ascii").rstrip("=")
     assert "=" not in encoded
     assert _is_valid_thought_signature(encoded) is True