I have multiple PDF files, I'm thinking about creating a separate VectorstStoreIndex for each file. and then using following? Is this the right approach to go with? I'm hopting to increase the retrieval accuracy across multiple PDFs.

graph = ComposableGraph.from_indices(
SimpleKeywordTableIndex,
[pdf1_index, pdf2_index],
index_summaries=[pdf1_summary, pdf2_summary],
max_keywords_per_chunk=50
)

Hi all,
I want to add summary of each node to it's metadata and embed them altogether. How do I do it?
I'm doing this to improve the retrieval accuracy, Is this the right approach?