I cannot put it any more clearly than this comment from CL at writedit's blog:
Image the reviewer as you…or worse. Imaging the person you are writing for is someone who is stressed about their funding, trying to get papers out that are getting rejected, overworked and tired, fighting to get the right people in the lab, juggling teaching/clinical work, getting flack from their spousal equivalence unit for not helping out, their dog bit them, they are stuck in a middle seat in coach on the way to study section and sleep deprived. NOW they are picking up your grant to read.
about all I have to add is to note that this person is, furthermore, not a specific expert in your subfield.
If you can't write clearly enough to get this person excited, your odds are somewhat lower than dodgy.