From 2403fa93845f0262606bbee2548c2f9044fcdd8c Mon Sep 17 00:00:00 2001
From: libaojiang <2461443384@qq.com>
Date: Mon, 12 Oct 2026 23:09:45 +0800
Subject: [PATCH] chore(vertex_ai): drop redundant isinstance after cast in id
 check

basedpyright counts the str isinstance as reportUnnecessaryIsInstance
now that the id carries a str cast, and the type gate rejects any
growth over the merge-base count.
---
 litellm/litellm_core_utils/prompt_templates/factory.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/litellm/litellm_core_utils/prompt_templates/factory.py b/litellm/litellm_core_utils/prompt_templates/factory.py
index 33e2bf03578..c0ce348dcb0 100644
--- a/litellm/litellm_core_utils/prompt_templates/factory.py
+++ b/litellm/litellm_core_utils/prompt_templates/factory.py
@@ -1329,7 +1329,7 @@ def get_thought_signature_from_tool(tool: Mapping[str, object]) -> str | None:
     tool_call_id: Final = cast(  # cast-ok: tool IDs come from model responses
         str, tool.get("id")
     )
-    if tool_call_id and isinstance(tool_call_id, str):
+    if tool_call_id:
         _, signature = _decode_tool_call_id_with_signature(tool_call_id)
         return signature
     return None