Given that the main product of federally-funded research is typically publications, Princeton University suggests that it would seem sensible to allow submission of PDFs of publications where they have already appeared as a result of the work funded by the grant, and reduce the reliance on extensive research summaries. If nothing has been published, then it makes sense to ask for a report on preliminary progress.
NSF is particularly burdensome in this regard; most of the questions on the yearly report seem redundant, and can take hours to complete. Where publications exist, it would appear to be sufficient to I) write a summary of 1-2 paragraphs of the research accomplished, II) list publications (and other significant presentations, etc.) that are outcomes of the research, and III) list the people involved.