May be I am missing something, but why write the whole "Merge pull request #so from so and so" ? Instead it could be something more succinct like "#$pr_num $title \n $ from $from \n $pr_repo_desc \n $body" or something like that (considering python has some equivalent of string interpolation). The first line becomes the title of commits which is much less informative with "Merge p....." and since commit authors are the people from whom the PR is "usually", may be mentioning it in the title can be less useful than somewhere else if at all ?