word usage - How to write this sentences in a work proposal?

I am writing a formal work proposal, and I have a question about how to list the items in the index of my proposal. Because English is not my first language (Spanish is), I'd like some help making sure I index these correctly.

For example, in my index, should I use:

• Description of the project or Project Description



• Benefits of this proposal or Proposal benefits


• Preliminary schedule of the project or just Preliminary schedule

Are there any rules or guidelines that would help me know the best way to set up my index for entries that could be listed in more than one way?

Answer

Risking to express a controversial opinion, I would say that technical documentation has slightly different priorities than normal texts. Being in I.T., I read and write tons of technical papers, and I always prefer readability and text size versus formal grammar.

Think for a moment, your reader is often a non-native speaker as well, but, most certainly, they are a busy person. Overuse of large grammar constructs may just increase the size of your writing, without adding any value.

No, I don't say your document should be ungrammatical. Instead, it must be based on keywords, the shorter the better (unlike my answer :-)
Let's review individual phrases (I took those from your original edit):

• Description of the Project vs. Project Description — are you really sure that project is strongly necessary? If you leave just Description, wouldn't it make your documentation more succinct? I think, it would; There's also special terms, purpose and abstract to denote sections containing verbose description of a project and its rationale;


• Justification of the project — I wouldn't use justification at all. It has several meanings, and you may confuse your reader. Alternatively, it may be review, analysis, or clarification, depending on the context;


• Definition of the scope of the project — there's a term, Scope of Work;


• Bounding of the projects — use Special Requirements or Dependencies instead;


• Benefits of this proposal — just a keyword, benefits, seems to be sufficient (indeed, if not of this proposal, of what then?);


• Competitive Advantages — it's a term by itself, stick to it;


• Deliverables of the project — Deliverables and Artifacts are standard terms;


• Preliminary schedule of this project — just schedule. Everyone understands that it your schedule is proposed, therefore it is subject for change, and, because of that, is preliminary;

Summarizing: