Increase the top_k parameter value.

Experiment with the hybrid search (dense + sparse embeddings), It will be beneficial for keyword search results. Note you need to change the similarity metric to "dot-product" for this. Source : https://docs.pinecone.io/guides/data/understanding-hybrid-search

Add metedata in the indexing part and for inferencing you can filter the results based on the metadata. Source : https://docs.pinecone.io/guides/data/understanding-metadata