Just tested this small python snippet to produce map package (*.mpk) from ArcGIS 10.3 Desktop . This package will not reveal full extent of layers in a MXD but only the extent you want.

Map packages lets you share your saved MXDs to everyone, including ArcGIS Online with all the layers, symbols and text. This package is a collection of all the active and inactive layers of the saved .mxd. The package is just like sharing everything in a zipped folder but in an ‘ArcGIS’ way. Check this out!

To make each MXD into separate mpk recursively use this instead,

PackageMap_management is a tool from package management toolset of Data management Toolbox. It let’s you make packages from MXDs with few options including some clever one. One of them is setting the output extent.

Notice that I wrote "DISPLAY" at one point of the code. We can use four types extent parameter,

  • MAXOF —Union of inputs
  • MINOF —Intersection of inputs
  • DISPLAY —Same extent as current display
  • <Layer> —Same extent as specified layer

You can also use X-Min Y-Min X-Max Y-Max to set the extent coordinates. If you have multiple dataframes in your layout, select the desired one to set the extent. Also fill the title, summery and description in the map property window. The mpk package is helpful to those who wants to save and share the layers with all the symbology and text styles to someone else. It is quite useful to store your layers and data after you finish your mapping project and share the ability to find the final maps from exactly where you left them. See here for more parameters of  PackageMap_management.