public static Task <CompletionDescription> GetDescriptionAsync(CompletionItem item, Document document, SymbolDescriptionOptions displayOptions, CancellationToken cancellationToken)
=> SymbolCompletionItem.HasSymbols(item)
? SymbolCompletionItem.GetDescriptionAsync(item, document, displayOptions, cancellationToken)
: Task.FromResult(CommonCompletionItem.GetDescription(item));