def _create_input_kwargs_from_args_spec(
        args_key, args_spec, validator):
    """Helper function to return kwargs for most model inputs.

    Args:
        args_key: The args key of the input from which a kwargs
            dict is being built.
        args_spec: The ARGS_SPEC object to reference.
        validator: The validator callable to provide to the ``validator`` kwarg
            for the input.

    Returns:
        A dict of ``kwargs`` to explode to an ``inputs.GriddedInput``
        object at creation time.
    """
    model_spec = args_spec['args']
    return {
        'args_key': args_key,
        'helptext': model_spec[args_key]['about'],
        'label': model_spec[args_key]['name'],
        'validator': validator,
    }