You receive the same level of documentation as you would by regular mail. The most common use of linear constraints is for placing upper and lower bounds on holdings for a group of assets. Even more general statements on holdings can be made using linear constraints. Everyone knows that in order to achieve higher rewards, one must assume greater risk. And different levels of risks are appropriate for different investors.
Diversification can provide some hedge against the volatility of the individual assets.
With many assets to choose from and the complex relationships between them, it is almost impossible to find an optimal portfolio by hand. This problem falls into the realm of Markowitz, or mean-variance, optimization. In brief, for a specified level of risk, we seek the portfolio with the highest expected return. Alternatively, for a desired level of return, we seek the portfolio with the lowest level of risk. Ideally one would like to see the efficient frontier , which displays the entire range of optimal portfolios, one for each level of assumed risk.