just redo all of it from scratch

lib/mcp/shared/instrumentation.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module MCP
+  module Instrumentation
+    def instrument_call(method, &block)
+      start_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+      begin
+        @instrumentation_data = {}
+        add_instrumentation_data(method:)
+
+        result = yield block
+
+        result
+      ensure
+        end_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+        add_instrumentation_data(duration: end_time - start_time)
+
+        configuration.instrumentation_callback.call(@instrumentation_data)
+      end
+    end
+
+    def add_instrumentation_data(**kwargs)
+      @instrumentation_data.merge!(kwargs)
+    end
+  end
+end