xinetd + shell script echoing flags in TCP packet

I'm trying to create a script that replicates a JSON status response from a Minecraft server (https://wiki.vg/Server_List_Ping) . I've currently set up xinetd to execute a shell script that echos a preset back, but I'm having trouble crafting the TCP packet. For some reason it returns whatever comes after echo, ignoring any flags. Here's a stripped down case that replicates the issue: /usr/bin/mc

#!/bin/sh

# hello!
echo -en "\x68\x65\x6c\x6c\x6f\x21"

/etc/xinetd.d/minecraft

service minecraft
{
  type = UNLISTED
  instances = 20
  socket_type = stream
  protocol = tcp
  wait = no
  user = root
  group = root
  server = /usr/bin/mc
  port = 25565
  disable = no
}

TCP reply data as seen from the client that initiated the request:

00000000: 2d65 6e20 5c78 3638 5c78 3635 5c78 3663  -en \x68\x65\x6c
00000010: 5c78 3663 5c78 3666 5c78 3231 0a         \x6c\x6f\x21.

Do I need to read the client request first, or is echo aliased to something else if called from xinetd?