The screenshot attached definitely seems to indicate that the issue is with the agent being missing from the autodeploy image, doesn't that directly contradict the KB article below?
vCloud Director releases earlier than 5.5 installed an agent on each ESXi host they managed. Beginning with vCloud Director 5.5, the system no longer requires that agent on ESXi 5.5 hosts unless the host must support creation of vCloud Network Isolation...."
