UserParameter: return empty

[LovingFox]

When I test "UserParameter" locally it looks good:

root@client1:~# zabbix_agentd -t hilink.discovery
hilink.discovery                              [t|{"data":[{"{#HILINKNAME}": "eth11"},{"{#HILINKNAME}": "eth12"},{"{#HILINKNAME}": "eth13"}]}]

But when server requests the same the agent returns this:

Nov 19 14:49:56 client1 zabbix_agentd[24025]: EXECUTE_STR() command:' hilink_discovery' len:11 cmd_result:'{"data":[]}'
Nov 19 14:49:56 client1 zabbix_agentd[24025]: Sending back [{"data":[]}]

What is the problem?

Agent Config:

...
UserParameter=hilink.discovery, hilink_discovery
...

Script "hilink.discovery":

#! /bin/sh

IFACES=$(uci -q show hilink | sed -n -E 's/hilink.(.*)=interface/\1/p')
NUM=$(echo "$IFACES" | wc -w)

echo -n '{"data":['
COUNT=0
for iface in $IFACES; do
   echo -n "{\"{#HILINKNAME}\": \"$iface\"}"
   COUNT=$(( $COUNT + 1  ))
   [ $COUNT -eq $NUM ] || echo -n ","
done
echo ']}'

[LovingFox]

Managed out to find the problem: agent's permissions...