However, the variability among reviewers is very high. Any division between concept, investigator and protocol is largely artificial. Read them and follow them carefully. Title can be highly focused but may have to be changed in competitive renewal, if you finish or change direction.
Global titles project broad scope, long range planning.
Convey formulation and testing of hypotheses, if appropriate. Be critical and provocative but never hostile. With the problem reviewed and defined, present a clear statement of what gap in knowledge your work will fill. Cite relevant published work in the field. Never artificially adopt the purpose and significance of your proposed research to meet the stated, implied or suspected objectives of the granting institute.