def valid_tags(tag_list, invalid):
    """
    Summary:
        checks tags for invalid chars
    Args:
        tag_list (list): starting list of tags
        invalid (list): list of illegal characters that should not be present in keys in tag_list
    Returns:
        Success | Failure, TYPE: bool
    """
    for tag in tag_list:
        for char in invalid:
            if char in tag['Key']:
                return False
    return True