The agentic reflect expand tool: drill previously retrieved memories up the hierarchy. "chunk" (the default) returns each memory with its provenance and the neighbouring memories of the same document, the surrounding context a truncated fact is missing; "document" returns the owning document's title and text. The id list is model-controlled, so it is de-duplicated, filtered to valid ids and capped before any query runs. cited_ids/1 lists every memory id an expansion put in front of the model, for grounding.