diff --git a/litellm/types/proxy/guardrails/guardrail_hooks/singulr.py b/litellm/types/proxy/guardrails/guardrail_hooks/singulr.py
index 13823b7e8e9..8ed85b63208 100644
--- a/litellm/types/proxy/guardrails/guardrail_hooks/singulr.py
+++ b/litellm/types/proxy/guardrails/guardrail_hooks/singulr.py
@@ -3,7 +3,10 @@ from typing import Any, Literal
 
 from pydantic import BaseModel, Field
 
-from litellm.types.llms.openai import ChatCompletionToolParam
+from litellm.types.llms.openai import (
+    ALL_RESPONSES_API_TOOL_PARAMS,
+    ChatCompletionToolParam,
+)
 
 from .base import GuardrailConfigModel
 
@@ -37,7 +40,7 @@ class SingulrGuardrailPayload(BaseModel):
     guardrail_scope: str | None = None
     messages: Sequence[Any] | None = None
     images: Sequence[str] | None = None
-    tools: Sequence[ChatCompletionToolParam] | None = None
+    tools: Sequence[ChatCompletionToolParam | ALL_RESPONSES_API_TOOL_PARAMS] | None = None
     response: Any = None  # pyright: ignore[reportExplicitAny]  # logging_only reports raw litellm callback results (ModelResponse, EmbeddingResponse, etc.)
     metadata: Mapping[str, Any] | None = None
 
diff --git a/tests/test_litellm/proxy/guardrails/guardrail_hooks/test_singulr.py b/tests/test_litellm/proxy/guardrails/guardrail_hooks/test_singulr.py
index 4996fe38dba..256170566fc 100644
--- a/tests/test_litellm/proxy/guardrails/guardrail_hooks/test_singulr.py
+++ b/tests/test_litellm/proxy/guardrails/guardrail_hooks/test_singulr.py
@@ -212,6 +212,30 @@ class TestSingulrRequestPayload:
         sent_payload = mock_post.call_args.kwargs["json"]
         assert sent_payload["tools"] == tools
 
+    @pytest.mark.asyncio
+    async def test_responses_api_mcp_tools_are_forwarded(self, singulr_guardrail):
+        """Regression: Responses API tools (e.g. {"type": "mcp", "server_label": ...})
+        have no "function" key, unlike Chat Completions tools. SingulrGuardrailPayload
+        rejected them with a pydantic ValidationError, turning every Responses API
+        request carrying an MCP tool into a 500."""
+        resp = _make_response({"should_block": False})
+        tools = [
+            {
+                "type": "mcp",
+                "server_label": "docs-server",
+                "server_url": "https://mcp.example.com",
+                "allowed_tools": ["search_docs"],
+            }
+        ]
+        with patch.object(singulr_guardrail.async_handler, "post", return_value=resp) as mock_post:
+            await singulr_guardrail.apply_guardrail(
+                inputs={"texts": ["How do I reset my password?"], "tools": tools},
+                request_data={},
+                input_type="request",
+            )
+        sent_payload = mock_post.call_args.kwargs["json"]
+        assert sent_payload["tools"] == tools
+
     @pytest.mark.asyncio
     async def test_user_api_key_alias_is_forwarded_in_metadata(self, singulr_guardrail):
         """Regression: the alias must be sent as {"user_api_key_alias": <alias>},