All publishers require that a manuscript has to be "satisfactory" before it will be accepted. This allows them to terminate a contract if the manuscript delivered is not fit for publication. While it makes sense that the publisher should be allowed to reject a work if it is not fit for publication, it's important to define this term in more detail in order to ensure that the publisher cannot reject the work for arbitrary reasons.
First, make sure you describe in much detail as possible what you are supposed to be delivering. Next, add "in form and content" after "satisfactory", which prevents the publisher from rejecting a work simply because the subject matter is no longer popular at the time you deliver the it.