A. Financial: This is simple, if the amount of money you receive in player salary in a trade outnumbers your FA available money, you can't do the trade. For instance
PHI has 5 million in FA money, and he receives a 7 million dollar player in a trade without getting 2 million, giving a 2 million+ player(s), or a combination of both, he cannot do said trade
IV. Hints when you are trading
A. Consider the financial consequences. A trade is not only based on talent, money is a very big factor in trading. Always be sure to consider whether trading your 3.0 SP making 350k is worth upgrading to a 4.0, but absorbing 12.5 million in salary. Some times are in dire straits because they did not consider salary problems. Sometimes, finances can be more important then talent.
V. Financials
OK, here is how to judge if you can do a trade financially. With the new format, it is easy.
The team that takes on less salary has no problems, so this is only to the team taking on more salary.
Look at the format, specifically the subtotals of annual salary. Take the higher subtotal and subtract the lower subtotal, and compare it to your available FA money. If the subtotal amount is more then your available FA money, you cannot do a trade, if it is less, you can do a trade, for instance
PHI gives:
Player X (9,000,000, SP, 4.5)
HOU gives:
Player Y (1,000,000, 2B, 3.5)
OK, HOU receives the 9m dollar SP, so they take on 9 million dollars (SP) - 1 million dollars (2B), meaning they have to take on 8 million dollars.
HOU total FA money: 4,584,403
In this case, 8 million is more then the 4.5 million and change, so they could not make this trade.