Here’s an example of how a wordy, negative paragraph could be recast more plainly and positively:
Elaborate or unnecessarily voluminous offers are not desired. Offerors are encouraged to take care in completely answering questions and offer requirements and to avoid submitting extraneous materials that do not show how the offeror is able to meet requirements.
Please keep your proposal brief, focusing only on answering the questions in this RFP and showing how you meet our requirements.
Would that have been so difficult?