One click down the tree from "Using x2go" (http://wiki.x2go.org/doku.php/doc:usage:start ) in the server section is the following wording.

When starting a new session the script called x2gostartagent gets executed on the server.

If usage doesn't require invoking x2gostartagent, perhaps this information should not be under the usage section. If there is API usage (for client customization) or x2go client development usage (by x2go contributors) may be that information should be sections relevant to those kinds of needs.

---------- Forwarded message ----------
From: Reinhard Tartler <siretart@gmail.com>
Date: Mon, Mar 3, 2014 at 7:52 AM
Subject: Re: [X2Go-User] Fwd: x2gostartagent command argument
To: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
Cc: Brian Lim <brian.lim.ca@gmail.com>, "x2go-user@lists.berlios.de" <x2go-user@lists.berlios.de>

Package: x2goserver

On Mon, Mar 3, 2014 at 7:09 AM, Mike Gabriel
<mike.gabriel@das-netzwerkteam.de> wrote:

> Don't call x2gostartagent directly. Use X2Go Client (or PyHoca-GUI /
> PyHoca-CLI) for launching server-side sessions.

In this case, those utilities should really be out of the default
search for commands $PATH. I'm BCC'ing submit@bugs.x2go.org with this
email.

--
regards,
Reinhard