Build a Small RAG Knowledge Tool

How to build a lightweight retrieval-augmented knowledge tool with grounded answers, source citations, narrow scope, and a realistic MVP.

March 16, 2026 · 6 min · Michelle
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The Smart Part Was the Memory, Not the Controller

TL;DR for operators A deployed model encounters a familiar operating condition again. Should it relearn the task, search for a saved configuration, or let a trained controller decide which parameters to reuse? The paper’s strongest result points to the simpler mechanism. Removing the searchable store of compressed task-specific configurations increased recovery from 1.27 to 13.33 adaptation steps—close to the 14.27 steps required by a baseline without that store. The component that looks least intelligent therefore accounts for most of the recovery advantage: retaining the small parameter modules that worked before and restoring them when the task returns. The paper calls this store the TaskKnowledgeBank. ...

August 1, 2026 · 9 min · Zelina
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The Lesson Plan Is the Product

TL;DR for operators AI learning is usually sold as a volume story: more data, more retrieval, more reasoning tokens, more reinforcement learning. Comforting. Also incomplete. Three recent papers make a more useful point. The model does not merely need more exposure. It needs a better lesson plan. One paper shows that a model can be given a more meaningful difficulty ranking for training examples, yet still fail to beat ordinary full-data training unless scoring and pacing are engineered together. Another shows that travel-planning agents become more factually grounded when forced into retrieval, but that the burden of grounding can damage instruction retention and preference satisfaction. A third shows that legal AI systems can be rewarded for correct prosecution outcomes without learning the underlying discrimination process that separates evidence insufficiency, statutory non-liability, discretionary non-prosecution, and prosecution. ...

June 25, 2026 · 16 min · Zelina
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The Retriever Found Similar Things. The Evidence Was Elsewhere.

TL;DR for operators The current enterprise RAG conversation still has a charmingly stubborn misconception: if the model hallucinates, buy better embeddings, increase the context window, add an agent, and hope the PowerPoint becomes true. The two papers here point in a less theatrical direction. One paper, Non-negative Elastic Net Decoding for Information Retrieval, argues that dense retrieval has a structural weakness: it scores each candidate independently, so it can retrieve several similar items instead of the complementary set actually needed to answer the query.1 The other, Agentic Hybrid RAG for Evidence-Grounded Muon Collider Analysis, shows what happens when retrieval is treated as a full evidence workflow: sparse and dense retrieval are fused, queries are decomposed under constraints, evidence is deduplicated and budgeted, and answers are judged for coverage, hallucination, and abstention.2 ...

June 23, 2026 · 19 min · Zelina
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Graph Work, Not Graph Worship: RAGA Turns RAG Into an Auditable Knowledge Operation

TL;DR for operators RAGA is not another “add a graph and accuracy goes up” paper. That would be too convenient, and therefore suspicious. The useful idea is more operational: treat retrieval-augmented generation as a knowledge management process, not a pile of embeddings with a polite chatbot on top. The paper proposes RAGA, short for Reading-And-Graph-building-Agent, an autonomous system that reads documents, searches existing graph knowledge, verifies whether new entities or relations should be added, and then constructs or updates a knowledge graph with source-linked provenance.1 Its core loop is Read–Search–Verify–Construct, implemented as a ReAct-style tool-calling agent rather than a one-shot extraction pipeline. ...

June 16, 2026 · 20 min · Zelina
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Search, Critique, Repeat: Critic-R Turns RAG Complaints into Retriever Training

Search failure is boring until it becomes expensive. A research agent asks for evidence. The retriever returns documents. The reasoning model reads them, continues writing, and eventually produces a confident answer. Somewhere in the middle, the evidence was slightly wrong: not irrelevant enough to trigger an obvious failure, not useful enough to support the next reasoning step. The agent proceeds anyway, because that is what agents do when we dress up uncertainty as workflow automation. ...

June 8, 2026 · 17 min · Zelina
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Memory Lane Has Potholes: MemFail and the Business of Testing Agent Recall

Memory is where enterprise AI demos go to become operationally embarrassing. In the demo, the assistant remembers that a client prefers concise weekly updates, that a trader avoids high-leverage positions after volatility spikes, or that a procurement manager only approves a supplier when compliance documents are current. In production, the same assistant may remember the attractive half of the fact and quietly lose the condition. It recalls “approves supplier” but forgets “only when compliance documents are current.” Congratulations: the agent has not forgotten. It has remembered dangerously. ...

June 4, 2026 · 15 min · Zelina
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Don’t Average the Needle: Spectral Retrieval and the RAG Evidence Problem

Enterprise search has a very old habit wearing a very modern jacket: it averages. A policy document becomes one vector. A runbook becomes one vector. A postmortem full of operational detail becomes one vector. Then a RAG system asks that one vector whether the document is relevant. This is convenient, fast, and usually defensible — until the relevant answer is a narrow paragraph hiding inside a large document. At that point, the retrieval system is no longer searching for evidence. It is asking a crowd to speak for the witness. ...

May 30, 2026 · 16 min · Zelina
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Provenance, Not Providence: Why AI Answers Need Receipts

Opening — Why this matters now The current AI market has become very good at producing fluent answers and very bad at explaining where those answers came from. This is not a minor inconvenience. It is the difference between an assistant that can be trusted in an operational workflow and an assistant that merely performs confidence with attractive typography. ...

May 9, 2026 · 14 min · Zelina
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Receipts, Please: RAG’s New Evidence Stack

Opening — Why this matters now The original business pitch for retrieval-augmented generation was wonderfully simple: connect the model to your documents, ask questions, get grounded answers. No need to retrain the model. No need to wait for the next foundation-model release. Just give the chatbot some files and let productivity bloom. ...

May 7, 2026 · 17 min · Zelina