What type of abstract includes a summary of the purpose and scope of a document?

A descriptive abstract provides a concise summary of the purpose and scope of a document. It typically includes the main objectives and the key points that are covered, allowing readers to gauge whether the document is relevant to their interests or needs. This type of abstract serves as a tool for quickly understanding the essence of the document without delving into the specifics, which is particularly useful in research and technical writing contexts.

The other options serve different functions. An informative abstract, for instance, goes beyond simply summarizing the purpose and scope; it also includes key results and conclusions from the document. An executive summary is more comprehensive than a descriptive abstract and presents a brief of the entire report, often intended for stakeholders. Finally, a closing summary serves to reiterate and consolidate the information presented towards the end of a document, rather than providing an overview at the beginning. Thus, a descriptive abstract accurately matches the definition provided in the question.