I use depot_tools for the "git cl *" functionality, but I almost never run 'gclient' so I never see automatic updates. It would be very helpful if running "git cl *" and similar commands occasionally checked for available updates and then informed the user that such updates were available (optimally it would do the update itself), and explained how to get the updates.

For example, the gcloud tool does this very well:

    Updates are available for some Cloud SDK components.  
    To install them,  please run:
        $ gcloud components update