Galaxy has been able to load tools after installation for quite some time,
however that did not work for production setups that are using multiple
job handler threads.
We did indeed refine the tool loading to work for production servers starting with release 16.10
Aspects of this have been refined up to release 17.05, which should be the most reliable concerning this feature.
No special options need to be set to use this, it should hopefully just work.
Technically we watch the various shed_tool_conf.xml / tool_conf.xml files as well as the individual tool wrappers for changes
and trigger a reload, which we speed up by caching the tool definitions.
One thing we can't do at the moment is detect if a macro file that is included in a tool has changes,
so in this case you'd still need to restart the galaxy instance unfortunately.
in the galaxy.ini that allows you to watch a directory of tools
(i.e no installation from the toolshed or modification of a tool_conf,xml file necessary) that you can activate.
If you want to use this feature you need to indicate in your tool_conf.xml file which directory you would like to monitor.
The syntax is like this:
<tool_dir dir="<directory to monitor>" recursive="true"/>
(The recursive="true" is not necessary if you want to monitor a flat directory).