How to enhance merge commit message ?

Hello list,

git's git repo contains a lot of merges with nice commit message, 
like this (d96497b8d):

Merge branches 'jc/merge-base', 'sp/merge', 'jc/diff', 'jc/explain', 'jc/web' 
and 'jc/pickaxe' into pu
    
    * jc/merge-base:
      Teach "git-merge-base --check-ancestry" about refs.
      git-merge-base: --check-ancestry option
    
    * sp/merge:
      Avoid git-fetch in `git-pull .` when possible.
    
    * jc/diff:
      test-para: combined diff between HEAD, index and working tree.
      para-walk: walk n trees, index and working tree in parallel
    
    * jc/explain:
      git-explain
....

How can I made the same messages using git pull . <branch> ?