Merge pull request #17570 from BerriAI/litellm_fix_mcp_test

litellm/proxy/_experimental/mcp_server/mcp_server_manager.py

@@ -1272,15 +1272,16 @@ class MCPServerManager:
         prefix = get_server_prefix(server)
 
         for tool in tools:
-            prefixed_name = add_server_prefix_to_name(tool.name, prefix)
+            tool_copy = tool.model_copy(deep=True)
 
-            name_to_use = prefixed_name if add_prefix else tool.name
+            original_name = tool_copy.name
+            prefixed_name = add_server_prefix_to_name(original_name, prefix)
 
-            # Preserve all tool fields including metadata/_meta by mutating the original tool
-            # Similar to how _create_prefixed_prompts works
-            original_name = tool.name
-            tool.name = name_to_use
-            prefixed_tools.append(tool)
+            name_to_use = prefixed_name if add_prefix else original_name
+
+            # Preserve all tool fields including metadata/_meta by avoiding mutation
+            tool_copy.name = name_to_use
+            prefixed_tools.append(tool_copy)
 
             # Update tool to server mapping for resolution (support both forms)
             self.tool_name_to_mcp_server_name_mapping[original_name] = prefix
@@ -1952,9 +1953,9 @@ class MCPServerManager:
                             server_name_from_prefix
                         ):
                             return server
-                    elif normalize_server_name(server.server_name) == normalize_server_name(
-                        server_name_from_prefix
-                    ):
+                    elif normalize_server_name(
+                        server.server_name
+                    ) == normalize_server_name(server_name_from_prefix):
                         return server
 
         return None

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

@@ -10,7 +10,13 @@ sys.path.insert(0, "../../../../../")
 
 import httpx
 from mcp import ReadResourceResult, Resource
-from mcp.types import GetPromptResult, Prompt, ResourceTemplate, TextResourceContents
+from mcp.types import (
+    GetPromptResult,
+    Prompt,
+    ResourceTemplate,
+    TextResourceContents,
+    Tool as MCPTool,
+)
 
 from litellm.proxy._experimental.mcp_server.mcp_server_manager import (
     MCPServerManager,
@@ -995,10 +1001,11 @@ class TestMCPServerManager:
         manager._create_mcp_client = MagicMock(return_value=object())
 
         # Tools returned upstream (unprefixed from provider)
-        upstream_tool = MagicMock()
-        upstream_tool.name = "send_email"
-        upstream_tool.description = "Send an email"
-        upstream_tool.inputSchema = {}
+        upstream_tool = MCPTool(
+            name="send_email",
+            description="Send an email",
+            inputSchema={},
+        )
 
         manager._fetch_tools_with_timeout = AsyncMock(return_value=[upstream_tool])
 
@@ -1025,14 +1032,16 @@ class TestMCPServerManager:
         )
 
         # Input tools as would come from upstream
-        t1 = MagicMock()
-        t1.name = "create_issue"
-        t1.description = ""
-        t1.inputSchema = {}
-        t2 = MagicMock()
-        t2.name = "close_issue"
-        t2.description = ""
-        t2.inputSchema = {}
+        t1 = MCPTool(
+            name="create_issue",
+            description="",
+            inputSchema={},
+        )
+        t2 = MCPTool(
+            name="close_issue",
+            description="",
+            inputSchema={},
+        )
 
         # Do not add prefix in returned objects
         out_tools = manager._create_prefixed_tools([t1, t2], server, add_prefix=False)
@@ -1066,10 +1075,11 @@ class TestMCPServerManager:
         manager.registry = {server.server_id: server}
 
         # Populate mapping (add_prefix value doesn't matter for mapping population)
-        base_tool = MagicMock()
-        base_tool.name = "create_zap"
-        base_tool.description = ""
-        base_tool.inputSchema = {}
+        base_tool = MCPTool(
+            name="create_zap",
+            description="",
+            inputSchema={},
+        )
         _ = manager._create_prefixed_tools([base_tool], server, add_prefix=False)
 
         # Unprefixed resolution