Jsonlines is an external to JSON format. You should split the data on lines and pass every line to the JSON parser separately. The same you should do with json.tool.

$ echo -e '{"ingredients":["frog", "water", "chocolate", "glucose"]}\n{"ingredients":["chocolate","steel bolts"]}' | while read -r line; do echo -n "$line" | python -m json.tool; done
{
    "ingredients": [
        "frog",
        "water",
        "chocolate",
        "glucose"
    ]
}
{
    "ingredients": [
        "chocolate",
        "steel bolts"
    ]
}