document mongo todos

Author: brettmc

src/Instrumentation/MongoDB/src/MongoDBInstrumentationSubscriber.php

@@ -136,6 +136,9 @@ private static function endSpan(?Throwable $exception = null): void
         $span->end();
     }
 
+    /**
+     * @todo In a load-balanced scenario, the hello response may be empty.
+     */
     public function serverChanged(ServerChangedEvent $event): void
     {
         $host = $event->getHost();

src/Instrumentation/MongoDB/src/MongoDBTraceAttributes.php

@@ -4,6 +4,10 @@
 
 namespace OpenTelemetry\Contrib\Instrumentation\MongoDB;
 
+/**
+ * @todo These attributes are not part of the specification and should be removed before this package goes stable,
+ * unless they are on the way to being added to the specification. See https://github.com/open-telemetry/opentelemetry-specification/blob/v1.40.0/specification/telemetry-stability.md
+ */
 interface MongoDBTraceAttributes
 {
     public const DB_MONGODB_MASTER = 'db.mongodb.master';