refactor: replace lowlevel Server decorators with on_* constructor kwargs (#1985)

tests/client/test_list_methods_cursor.py

@@ -3,9 +3,9 @@ from collections.abc import Callable
 import pytest
 
 from mcp import Client, types
-from mcp.server import Server
+from mcp.server import Server, ServerRequestContext
 from mcp.server.mcpserver import MCPServer
-from mcp.types import ListToolsRequest, ListToolsResult
+from mcp.types import ListToolsResult
 
 from .conftest import StreamSpyCollection
 
@@ -105,14 +105,16 @@ async def test_list_tools_with_strict_server_validation(
 
 async def test_list_tools_with_lowlevel_server():
     """Test that list_tools works with a lowlevel Server using params."""
-    server = Server("test-lowlevel")
 
-    @server.list_tools()
-    async def handle_list_tools(request: ListToolsRequest) -> ListToolsResult:
+    async def handle_list_tools(
+        ctx: ServerRequestContext, params: types.PaginatedRequestParams | None
+    ) -> ListToolsResult:
         # Echo back what cursor we received in the tool description
-        cursor = request.params.cursor if request.params else None
+        cursor = params.cursor if params else None
         return ListToolsResult(tools=[types.Tool(name="test_tool", description=f"cursor={cursor}", input_schema={})])
 
+    server = Server("test-lowlevel", on_list_tools=handle_list_tools)
+
     async with Client(server) as client:
         result = await client.list_tools()
         assert result.tools[0].description == "cursor=None"