> A non-summary PR/MR might lead to the question—“WHY is this code here?"
This is precisely what a (good) commit message should answer.
Commits are historical records, sure, but they can include metadata about the change, which should primarily explain why the change was made, what tradeoffs were made and why, and any other pertinent information.
This is useful not just during the code review process, but for posterity whenever someone needs to understand the codebase, while bisecting, etc. If this information is only in the PR, it won't be easy to reference later.
FWIW I'm not against short summaries in PRs that are exceptionally tricky to understand. The PR description is also useful as a living document for keeping track of pending tasks. But in the majority of cases, commit messages should suffice. This is why GitHub, and I'm sure other forges as well, automatically fill out the PR title and description with the commit information, as long as there's only one commit, which is the ideal scenario. For larger PRs, if it doesn't make sense to create multiple, I usually just say "See the commits for details".
This is precisely what a (good) commit message should answer.
Commits are historical records, sure, but they can include metadata about the change, which should primarily explain why the change was made, what tradeoffs were made and why, and any other pertinent information.
This is useful not just during the code review process, but for posterity whenever someone needs to understand the codebase, while bisecting, etc. If this information is only in the PR, it won't be easy to reference later.
FWIW I'm not against short summaries in PRs that are exceptionally tricky to understand. The PR description is also useful as a living document for keeping track of pending tasks. But in the majority of cases, commit messages should suffice. This is why GitHub, and I'm sure other forges as well, automatically fill out the PR title and description with the commit information, as long as there's only one commit, which is the ideal scenario. For larger PRs, if it doesn't make sense to create multiple, I usually just say "See the commits for details".