def description(path, string, yaml):
    """Verify that Workbooks and Workflows have descriptions"""
    if 'workflows' not in yaml:
        yield 'Probably not a workbook. Not supported. {}'.format(path)
        raise StopIteration
    W101 = 'W101: Workbook {} has no description'
    W102 = 'W102: Workflow {}.{} has no description'
    workbook = yaml['name']
    if 'description' not in yaml:
        yield W101.format(workbook)
    for workflow, struct in yaml['workflows'].items():
        if 'description' not in struct:
            yield W102.format(workbook, workflow)
