Well for starters you only really care about the serializable interface if you are planning on writing objects to file and back (I think it's a necessary for MASON checkpointing, but I could be wrong about that).
The idea is that if you implement Serializable (and if you extend Mason Geometry you do) is that you need to make sure all the fields of your Agent class are also serializable (writable to file). This is a bit confusing since Serializable is really a marker interface for some behind the curtain java stuff rather than your classic method interfaces.

There is a long description of what's needed here:

In practice however I didn't mean to scare anyone, this is really only needed when you are looking to generate persistent objects

On Wed, Mar 23, 2016 at 9:02 AM Luís de Sousa <[log in to unmask]> wrote:
On 23 March 2016 at 09:52, Nick Malleson <[log in to unmask]> wrote:
> Ernesto, what are the implications of having to make Agent serializable?

And would ask why it must be made serializable? I never did it myself...