It seems to me that you might as well put that thought and effort into describing the changes yourself. Most of my changes warrant 0-2 sentences of description below the header. A few particularly subtle bug fixes may need more to make sense of, but detailed descriptions of why certain mitigations are necessary are in my case more likely to end up as code comments.

That describing a change should frequently be such a difficult problem that instead of just doing it you prefer to put thought and effort into telling an LLM to do it smells bad to me. For me, the thought and effort spent writing a description is mostly already amortized through thinking clearly about the problem and performing the work. I have a much easier time describing what I just did and why than a machine that has no access to that information unless I tell it.