Custom Discovery Not Firing

[plui]

I have a custom discovery that calls a shell script. The script outputs the following:

{
"data":[
{ "{#DBNAME}":"collector", "{#APPUSER}":"admin"},
{ "{#DBNAME}":"demoDB", "{#APPUSER}":"admin"},
{ "{#DBNAME}":"demoDB", "{#APPUSER}":"Bill"},
{ "{#DBNAME}":"customer1", "{#APPUSER}":"admin"},
{ "{#DBNAME}":"customer1", "{#APPUSER}":"Bill"},
{ "{#DBNAME}":"customer2", "{#APPUSER}":"admin"}
  ]
}

For some reason it seems like the discovery is not firing because I can't see it discovered anything in the UI. I looked at the UI for any red boxes saying it's supported but didn't see any. I looked at zabbix_server.log and zabbix_agentd.log but neither have anything interesting.

I also tried executing the following just to make sure the agent can run the command:

/usr/sbin/zabbix_agentd -t my.test.discoveruser

Any idea?