An abstract is typically written at the completion of the paper but can be written in advance. You may not have a completed paper. In this case, your proposal should reflect your goals for the research. Or write as if the paper is complete. Use a snazzy title that combines personality and a clear sense of the project.
Proposals are persuasive.
You are trying to sell your idea to reviewers. Focus on the need for your topic as opposed to who or what causes the problem. Avoid jargon but use specific keywords to your field. Clarity is essential. Reread your proposal several times.