Missing desription of IO worker's server attributes

[standalone@localhost:9990 /] /subsystem=io/worker=default/server=*:read-resource-description
{       
    "outcome" => "success",
    "result" => [{
        "address" => [
            ("subsystem" => "io"),
            ("worker" => "default"),
            ("server" => "*")
        ],
        "outcome" => "success",
        "result" => {
            "description" => "description",
            "storage" => "runtime-only",
            "attributes" => {
                "connection-count" => {
                    "type" => INT,
                    "description" => "connection-count",
                    "expressions-allowed" => false,
                    "required" => true,
                    "nillable" => false,
                    "access-type" => "metric",
                    "storage" => "runtime"
                },
                "connection-limit-high-water-mark" => {
                    "type" => INT,
                    "description" => "connection-limit-high-water-mark",
                    "expressions-allowed" => false,
                    "required" => true,
                    "nillable" => false,
                    "access-type" => "read-only",
                    "storage" => "runtime"
                },
                "connection-limit-low-water-mark" => {
                    "type" => INT,
                    "description" => "connection-limit-low-water-mark",
                    "expressions-allowed" => false,
                    "required" => true,
                    "nillable" => false,
                    "access-type" => "read-only",
                    "storage" => "runtime"
                }
            },
            "operations" => undefined,
            "notifications" => undefined,
            "children" => {}
        }
    }]
}