Revert "Change default to double hyphen"

This reverts commit f49e7492c7.

docs/my-website/docs/mcp.md

@@ -569,7 +569,7 @@ mcp_servers:
 ### How It Works
 
 1. **Tool-specific filtering**: Each tool can have its own list of allowed parameters
-2. **Flexible naming**: Tool names can be specified with or without the server prefix (e.g., both `"getpetbyid"` and `"my_api_mcp--getpetbyid"` work)
+2. **Flexible naming**: Tool names can be specified with or without the server prefix (e.g., both `"getpetbyid"` and `"my_api_mcp-getpetbyid"` work)
 3. **Whitelist approach**: Only parameters in the allowed list are permitted
 4. **Unlisted tools**: If `allowed_params` is not set, all parameters are allowed
 5. **Error handling**: Requests with disallowed parameters receive a 403 error with details about which parameters are allowed

litellm/proxy/_experimental/mcp_server/utils.py

@@ -1,15 +1,16 @@
 """
 MCP Server Utilities
 """
-import importlib
+from typing import Tuple, Any
+
 import os
-from typing import Any, Tuple
+import importlib
 
 # Constants
 LITELLM_MCP_SERVER_NAME = "litellm-mcp-server"
 LITELLM_MCP_SERVER_VERSION = "1.0.0"
 LITELLM_MCP_SERVER_DESCRIPTION = "MCP Server for LiteLLM"
-MCP_TOOL_PREFIX_SEPARATOR = os.environ.get("MCP_TOOL_PREFIX_SEPARATOR", "--")
+MCP_TOOL_PREFIX_SEPARATOR = os.environ.get("MCP_TOOL_PREFIX_SEPARATOR", "-")
 MCP_TOOL_PREFIX_FORMAT = "{server_name}{separator}{tool_name}"
 
 
@@ -112,7 +113,9 @@ def is_tool_name_prefixed(tool_name: str) -> bool:
     return MCP_TOOL_PREFIX_SEPARATOR in tool_name
 
 
-def validate_mcp_server_name(server_name: str, raise_http_exception: bool = False) -> None:
+def validate_mcp_server_name(
+    server_name: str, raise_http_exception: bool = False
+) -> None:
     """
     Validate that MCP server name does not contain 'MCP_TOOL_PREFIX_SEPARATOR'.
 
@@ -129,6 +132,8 @@ def validate_mcp_server_name(server_name: str, raise_http_exception: bool = Fals
             from fastapi import HTTPException
             from starlette import status
 
-            raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail={"error": error_message})
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST, detail={"error": error_message}
+            )
         else:
             raise Exception(error_message)

tests/mcp_tests/test_mcp_server.py

@@ -1207,7 +1207,7 @@ async def test_mcp_server_manager_alias_tool_prefixing():
 
         # Verify tool is prefixed with alias
         assert len(tools) == 1
-        assert tools[0].name == "my_alias--send_email"
+        assert tools[0].name == "my_alias-send_email"
 
         # Verify mapping is updated correctly
         assert (
@@ -1215,7 +1215,7 @@ async def test_mcp_server_manager_alias_tool_prefixing():
             == "my_alias"
         )
         assert (
-            test_manager.tool_name_to_mcp_server_name_mapping["my_alias--send_email"]
+            test_manager.tool_name_to_mcp_server_name_mapping["my_alias-send_email"]
             == "my_alias"
         )
 
@@ -1267,7 +1267,7 @@ async def test_mcp_server_manager_server_name_tool_prefixing():
 
         # Verify tool is prefixed with server_name (normalized)
         assert len(tools) == 1
-        assert tools[0].name == "Test_Server--send_email"
+        assert tools[0].name == "Test_Server-send_email"
 
         # Verify mapping is updated correctly
         assert (
@@ -1275,7 +1275,7 @@ async def test_mcp_server_manager_server_name_tool_prefixing():
             == "Test Server"
         )
         assert (
-            test_manager.tool_name_to_mcp_server_name_mapping["Test_Server--send_email"]
+            test_manager.tool_name_to_mcp_server_name_mapping["Test_Server-send_email"]
             == "Test Server"
         )
 
@@ -1327,7 +1327,7 @@ async def test_mcp_server_manager_server_id_tool_prefixing():
 
         # Verify tool is prefixed with server_id
         assert len(tools) == 1
-        assert tools[0].name == "test-server-123--send_email"
+        assert tools[0].name == "test-server-123-send_email"
 
         # Verify mapping is updated correctly
         assert (
@@ -1336,7 +1336,7 @@ async def test_mcp_server_manager_server_id_tool_prefixing():
         )
         assert (
             test_manager.tool_name_to_mcp_server_name_mapping[
-                "test-server-123--send_email"
+                "test-server-123-send_email"
             ]
             == "test-server-123"
         )
@@ -1487,19 +1487,19 @@ def test_add_server_prefix_to_name():
 
     # Test basic prefixing
     result = add_server_prefix_to_name("send_email", "My Server")
-    assert result == "My_Server--send_email"
+    assert result == "My_Server-send_email"
 
     # Test with server name that already has underscores
     result = add_server_prefix_to_name("create_event", "my_server")
-    assert result == "my_server--create_event"
+    assert result == "my_server-create_event"
 
     # Test with empty name
     result = add_server_prefix_to_name("", "My Server")
-    assert result == "My_Server--"
+    assert result == "My_Server-"
 
     # Test with empty server name
     result = add_server_prefix_to_name("send_email", "")
-    assert result == "--send_email"
+    assert result == "-send_email"
 
 
 def test_get_server_auth_header_with_alias():

tests/test_litellm/proxy/_experimental/mcp_server/test_mcp_server.py

@@ -1088,7 +1088,7 @@ async def test_call_mcp_tool_user_unauthorized_access():
         # Try to call a tool from "restricted_server" - should raise HTTPException with 403 status
         with pytest.raises(HTTPException) as exc_info:
             await call_mcp_tool(
-                name="restricted_server--send_email",
+                name="restricted_server-send_email",
                 arguments={
                     "to": "test@example.com",
                     "subject": "Test",

tests/test_litellm/proxy/_experimental/mcp_server/test_mcp_server_manager.py

@@ -9,8 +9,6 @@ from fastapi import HTTPException
 sys.path.insert(0, "../../../../../")
 
 import httpx
-from mcp import ReadResourceResult, Resource
-from mcp.types import GetPromptResult, Prompt, ResourceTemplate, TextResourceContents
 
 from litellm.proxy._experimental.mcp_server.mcp_server_manager import (
     MCPServerManager,
@@ -19,6 +17,8 @@ from litellm.proxy._experimental.mcp_server.mcp_server_manager import (
 from litellm.proxy._types import LiteLLM_MCPServerTable, MCPTransport
 from litellm.types.mcp import MCPAuth
 from litellm.types.mcp_server.mcp_server_manager import MCPOAuthMetadata, MCPServer
+from mcp import ReadResourceResult, Resource
+from mcp.types import GetPromptResult, Prompt, ResourceTemplate, TextResourceContents
 
 
 class TestMCPServerManager:
@@ -1005,7 +1005,7 @@ class TestMCPServerManager:
         # Case 1: add_prefix=True (default for multi-server) -> expect prefixed
         tools_prefixed = await manager._get_tools_from_server(server, add_prefix=True)
         assert len(tools_prefixed) == 1
-        assert tools_prefixed[0].name == "zapier--send_email"
+        assert tools_prefixed[0].name == "zapier-send_email"
 
         # Case 2: add_prefix=False (single-server) -> expect unprefixed
         tools_unprefixed = await manager._get_tools_from_server(