What is Hypothetical Document Embeddings (HyDE)? How does asking the LLM to "write a fake answer first" improve the search results?

When would you store a summary of a document in the vector DB but retrieve the full text for the LLM?

How do you evaluate an agent when the "correct path" might involve 5 different tool calls in any order?

What is the fundamental difference between a "Chain" (hardcoded steps) and an "Agent" (model-decided steps)? When is a Chain actually better than an Agent?