diff --git a/litellm/proxy/_experimental/mcp_server/rest_endpoints.py b/litellm/proxy/_experimental/mcp_server/rest_endpoints.py
index 1481a027f4b..27a01ee3c30 100644
--- a/litellm/proxy/_experimental/mcp_server/rest_endpoints.py
+++ b/litellm/proxy/_experimental/mcp_server/rest_endpoints.py
@@ -1294,9 +1294,25 @@ if MCP_AVAILABLE:
 
         new_mcp_server_request = _inherit_credentials_from_existing_server(new_mcp_server_request)
 
+        def _preview_warnings(tool_names: List[str]) -> List[str]:
+            # In short-prefix mode the 3-char prefix derives from the server_id
+            # assigned at create time, so without one the final length is
+            # unknowable; skip speculative warnings (runtime exclusion still warns).
+            if is_short_mcp_tool_prefix_enabled() and not new_mcp_server_request.server_id:
+                return []
+            return tool_name_length_warnings(
+                tool_names,
+                get_server_prefix(new_mcp_server_request),
+                MCP_MAX_TOOL_NAME_LENGTH,
+            )
+
         # For OpenAPI spec servers, generate tools from the spec directly
         if new_mcp_server_request.spec_path:
-            return await _preview_openapi_tools(new_mcp_server_request.spec_path)
+            openapi_preview = await _preview_openapi_tools(new_mcp_server_request.spec_path)
+            return {
+                **openapi_preview,
+                "warnings": _preview_warnings([tool["name"] for tool in openapi_preview.get("tools") or []]),
+            }
 
         from litellm.proxy._experimental.mcp_server.auth.user_api_key_auth_mcp import (
             MCPRequestHandler,
@@ -1326,23 +1342,11 @@ if MCP_AVAILABLE:
             list_tools_response = await client.run_with_session(_list_tools_session_operation)
             list_tools_result: List[MCPTool] = list_tools_response.tools
             model_dumped_tools: List[dict] = [tool.model_dump() for tool in list_tools_result]
-            # In short-prefix mode the 3-char prefix derives from the server_id
-            # assigned at create time, so without one the final length is
-            # unknowable; skip speculative warnings (runtime exclusion still warns).
-            warnings = (
-                []
-                if is_short_mcp_tool_prefix_enabled() and not new_mcp_server_request.server_id
-                else tool_name_length_warnings(
-                    [tool.name for tool in list_tools_result],
-                    get_server_prefix(new_mcp_server_request),
-                    MCP_MAX_TOOL_NAME_LENGTH,
-                )
-            )
             return {
                 "tools": model_dumped_tools,
                 "error": None,
                 "message": "Successfully retrieved tools",
-                "warnings": warnings,
+                "warnings": _preview_warnings([tool.name for tool in list_tools_result]),
             }
 
         return await _execute_with_mcp_client(
diff --git a/tests/test_litellm/proxy/_experimental/mcp_server/test_rest_endpoints.py b/tests/test_litellm/proxy/_experimental/mcp_server/test_rest_endpoints.py
index 4d8248e6782..5243e457e0b 100644
--- a/tests/test_litellm/proxy/_experimental/mcp_server/test_rest_endpoints.py
+++ b/tests/test_litellm/proxy/_experimental/mcp_server/test_rest_endpoints.py
@@ -688,6 +688,40 @@ class TestTestToolsList:
 
         assert result["warnings"] == []
 
+    async def test_openapi_preview_flags_tool_names_exceeding_provider_limit(self, monkeypatch):
+        """The OpenAPI spec preview must carry the same length warnings as the MCP
+        preview, since registered OpenAPI tools get the server prefix too."""
+        from litellm.constants import MCP_MAX_TOOL_NAME_LENGTH
+        from litellm.proxy._types import LitellmUserRoles
+
+        alias = "network_config_audit"
+        fitting = "t" * (MCP_MAX_TOOL_NAME_LENGTH - len(alias) - 1)
+        too_long = "t" * (MCP_MAX_TOOL_NAME_LENGTH - len(alias))
+
+        async def fake_preview(spec_path):
+            return {
+                "tools": [{"name": fitting}, {"name": too_long}],
+                "error": None,
+                "message": "Found 2 tools from OpenAPI spec",
+            }
+
+        monkeypatch.setattr(rest_endpoints, "_preview_openapi_tools", fake_preview, raising=False)
+
+        result = await rest_endpoints.test_tools_list(
+            _build_request(),
+            NewMCPServerRequest(
+                server_name="example",
+                alias=alias,
+                spec_path="/tmp/spec.json",
+                auth_type=MCPAuth.none,
+            ),
+            user_api_key_dict=UserAPIKeyAuth(user_role=LitellmUserRoles.PROXY_ADMIN),
+        )
+
+        assert len(result["tools"]) == 2
+        assert len(result["warnings"]) == 1
+        assert f"{alias}-{too_long}" in result["warnings"][0]
+
 
 class TestListToolsRestAPI:
     pytestmark = pytest.mark.asyncio
diff --git a/ui/litellm-dashboard/src/hooks/useTestMCPConnection.tsx b/ui/litellm-dashboard/src/hooks/useTestMCPConnection.tsx
index 38e9679a850..96a65f63c2d 100644
--- a/ui/litellm-dashboard/src/hooks/useTestMCPConnection.tsx
+++ b/ui/litellm-dashboard/src/hooks/useTestMCPConnection.tsx
@@ -5,6 +5,7 @@ import { AUTH_TYPE, OAUTH_FLOW, TRANSPORT } from "@/components/mcp_tools/types";
 interface MCPServerConfig {
   server_id?: string;
   server_name?: string;
+  alias?: string;
   url?: string;
   spec_path?: string;
   transport?: string;
@@ -140,6 +141,7 @@ export const useTestMCPConnection = ({
       const mcpServerConfig: MCPServerConfig = {
         server_id: formValues.server_id || "",
         server_name: formValues.server_name || "",
+        alias: formValues.alias,
         url: formValues.url,
         spec_path: formValues.spec_path,
         transport: effectiveTransport,
@@ -214,6 +216,7 @@ export const useTestMCPConnection = ({
     formValues.spec_path,
     formValues.transport,
     formValues.auth_type,
+    formValues.alias,
     accessToken,
     enabled,
     oauthAccessToken,