How much detail the contract has to explain?

[ksshhs]

How much detail the contract has to explain?

Basically my bussiness is designing and consultant product for client.
But between me and client we have confidential agreement which I don't have right to explain anything about project to anyone.
So in the contract, it describes about what I can do, what I can't do and samething for client. Also it shows project title, client and my detail.

Would it be matter that doesn't explain what exactly I am designing??