Say no without wrecking the relationship

Someone has asked me for this:

A former colleague wants me to review a 40 page grant application by Friday, unpaid, and has already told the funder I'm involved.

My real reason for saying no: I don't have the time and honestly the project isn't very good
Where I want this to land: I want to offer something smaller instead

Write my reply.

- Say no in the first two sentences. No warm-up paragraph, no long throat-clearing before the answer.
- Be warm about them, clear about the answer. Those are separate jobs.
- Don't over-explain. One reason, not a defence.
- Match where I want this to land exactly. If I'm not offering an alternative, don't manufacture one to soften it.

If my real reason is something I can't say out loud, tell me so, and give me something true I can say instead. Don't invent an excuse for me.

Keep it under 120 words. Then, in one line, tell me how this reads to someone who was hoping for a yes.

What you get: A short reply that says no in the first two lines, and a read on how it lands.