[Koha] How to introduce a new user-permission to Koha?

[Markus Becker]

Dear Koha-Community,

i did not find any hint oder documentation, where the permissions for
using tools etc. are stored.

My example:
For testing purpose i want to insert my own perl-script into Koha and
it should appear on the "tools"-page.

The links on this page are shown to the user or not depending on the
permissions he has:
(tools-home.tt)

 [% IF ( CAN_user_tools_manage_staged_marc ) %]
 <dt><a href="/cgi-bin/koha/tools/bibliotheca_convert.pl">Bibliotheca-Datei
hochladen</a></dt>
 <dd>Werkzeug um BIBLIOTHECAplus-Exportdatei für den Import hochzuladen</dd>
 [% END %]

I can not find the place, where these rights are deposited. How does
Koha know if a certain right is existing?
I found the file permissions.inc but changes there did not having any effect.

Of cource i could use the permission
"CAN_user_tools_manage_staged_marc" for my own script (and then the
link is shown), but IMHO it would be not correct to "steal" the
permission of another script.

I would be very grateful if someone could give me a hint how to
introduce the permission to start my script to Koha.

Thank You very much in Advance,
Markus Becker