Apart from legal and other sanity aspects, consider common sense as another important prerequisite in drafting contracts. If some provision does not make common sense, question it from clients or other stakeholders involved.
Many a times, you may come across provisions of a contract which seem awkward to you – which are not in ordinary course of business or where any rates or terms and conditions are not what you usually see in common. The reasons for such terms can be many. In some cases, the parties may either be trying to achieve something impermissible, illegal, unethical, etc. or they may be pursuing some trade, customs or practice which is fine but you are not aware of it. Such terms could also be due to the different negotiating powers of the parties or a desperate situation one / more of them may be in.
There could be something fishy going around. If you let it go through without scrutiny, later on you could realise having become a party to an illegal transaction or relationship unknowingly / unwittingly.
If you question it, you are in a position to assess whether the parties’ actions are legal and proper – if there is a deviation, you may as well advise the parties as to how to plug it. Else, if the stakes are too high and there is a strong possibility of the transaction not passing the scrutiny of legality (at least), you may make a conscious choice of proceeding with or walking out of the assignment.