def get_roi_params(separation: str = "uplc", instrument: str = "qtof"):
    """
    Creates a dictionary with recommended parameters for the make_roi function
    in different use cases.

    Parameters
    ----------
    separation : {"uplc", "hplc"}
        Mode in which the data was acquired. Used to set minimum length of the
        roi and number of missing values.
    instrument : {"qtof", "orbitrap"}
        Type of MS instrument. Used to set the tolerance.

    Returns
    -------
    roi_parameters : dict
    """
    roi_params = {"min_intensity": 500, "multiple_match": "reduce"}

    if separation == "uplc":
        roi_params.update({"max_missing": 1, "min_length": 10})
    elif separation == "hplc":
        roi_params.update({"max_missing": 1, "min_length": 20})
    else:
        msg = "valid `separation` are uplc and hplc"
        raise ValueError(msg)

    if instrument == "qtof":
        roi_params.update({"tolerance": 0.01})
    elif instrument == "orbitrap":
        roi_params.update({"tolerance": 0.005})
    else:
        msg = "valid `instrument` are qtof and orbitrap"
        raise ValueError(msg)

    roi_params["mode"] = separation

    return roi_params