Vertex AI Search

Vertex AI Search & Summarization Best Practices

1. Mandatory Use of the Answer API (/answer):

   • Do NOT use the standard /search API if the goal is to generate summaries across multiple datastores.
   • Always implement the Answer API (AnswerQueryRequest), as it is explicitly designed to handle multi-datastore summarization and multi-step retrieval.

2. Multi-Datastore Configuration:

   • Ensure the API payload correctly passes multiple datastores using the dataStoreSpecs array to properly enable Blended Search.

3. Chunk Mode for Unstructured Data:

   • If querying unstructured datastores, the search request proto must be explicitly configured to feed chunked data to the LLM.
   • Set search_result_mode to CHUNK.
   • Configure the chunk_spec within the content_search_spec so the model knows how to process and summarize the cross-datastore chunks.

4. Bypass UI Limitations:

   • Be aware that the Google Cloud Console UI sometimes suppresses summary configurations for blended search or returns default errors if preview flags aren't enabled.
   • Always rely on direct REST API calls or official Google Cloud Client Libraries to validate summarization functionality rather than the Cloud Console UI.