Make VectorDB an implementation of Microsoft.Extensions.VectorData
Microsoft.Extensions.VectorData.Abstractions provides a core set of building blocks for working with vector stores.
Update existing implementation to implement VectorStore and VectorStoreCollection.
https://github.com/microsoft/mcp/blob/842d6bed7162ab37a0642134b3f07c305d584551/eng/tools/ToolDescriptionEvaluator/VectorDb/VectorDB.cs#L52-L253
While at the moment VectorDB is a custom in-memory implementation, by implementing the VectorStore and VectorStoreCollection base types, it makes it easy to replace the current implementation with any of the other existing providers with little to no code changes at a later time.
Additionally, it makes it easy to plug in Microsoft.Extensions.DataIngestion set of libraries for chunking, processing, and writing to the vector DB.