The easiest way to determine if your portfolio is optimal is to run Portfolio Optimizer several times replacing your current portfolio with resulted optimal portfolio after each iteration. You should stop this process when all relative scores of your portfolio are identical (or almost identical) to relative scores of the optimal portfolio.
Another way to determine if your portfolio is optimal is to run Portfolio Suggestion Module several times replacing your current portfolio with one of suggested optimal portfolio after each iteration. You should stop this process when risk and return characteristics of both portfolios are the same (i.e. current and optimal portfolios simply overlap each other on the risk/return graph)