LabourCrew: A Multi-Agent RAG Framework for Trustworthy Adversarial Deliberation and Statutory Reasoning over Labour Law
Organizations: Ahsanullah University of Science and Technology, Bangladesh · Jashore University of Science and Technology, Bangladesh · American International University - Bangladesh
Abstract
In statutory question answering, every claim must be traceable to evidence, not merely relevant, since unverifiable labour-rights answers carry serious legal consequences. Current systems fall short: single-pass RAG cannot detect insufficient evidence, while multi-agent legal-debate systems treat grounding as a prompting convention, letting agents cite unretrieved evidence. To address this gap, we introduce LabourCrew, a multi-agent RAG framework built around three grounding mechanisms: StatuteGraph, a graph index that explicitly links chapter, section, proviso, and cross-reference structure rather than fixed-length spans; an Evidence Exchange Protocol that confines advocates and an interpreter to an evidence ledger, making citation to unretrieved text impossible, while a fault-tolerant supervisor board runs advocates in parallel so individual failures degrade rather than crash the system; and a Calibrated Trust Gate that replaces categorical accept/reject decisions with a trust score, thresholded via conformal risk control for a distribution-free bound on the false-accept rate. We evaluate on LabourActQA, a 500-item Bangla question set from the Bangladesh Labour Act, 2006, spanning seven reasoning categories and three difficulty tiers. The framework drives the empirical false-accept rate to 0.081, within the target level (), achieves the highest Answer Relevancy among HyDE RAG, Graph-RAG, and Hierarchical RAG (0.862 0.839, 0.815, 0.828), and degrades gradually rather than catastrophically as question difficulty increases. These results show that calibrated abstention, not retrieval quality alone, is what makes legal question answering auditable in low-resource statutory domains.
Figures & tables
| Method / Configuration | N | Answer Relevancy | Context Relevancy | Context Precision | Context Recall | Noise Sensitivity |
|---|---|---|---|---|---|---|
| LabourCrew | 500 | 0.862 | 0.891 | 0.914 | 0.913 | 0.081 |
| w/o Trust Auditor | 500 | 0.839 | 0.880 | 0.879 | 0.904 | 0.121 |
| w/o Link Hopper | 500 | 0.842 | 0.829 | 0.844 | 0.844 | 0.129 |
| w/o Worker Counsel | 500 | 0.833 | 0.885 | 0.891 | 0.905 | 0.095 |
| w/o Employer Counsel | 500 | 0.846 | 0.887 | 0.902 | 0.908 | 0.089 |
| w/o Legal Interpreter | 500 | 0.838 | 0.882 | 0.894 | 0.904 | 0.094 |
| Category | N | Lat. (s) | Rounds | EC | PC | GVCP | TGLO | CBP |
|---|---|---|---|---|---|---|---|---|
| Direct Factual Retrieval | 78 | 19.7 | 1.00 | 0.949 | 0.979 | 1.000 | 100.0% | 0.763 |
| Definitional and Classification | 76 | 20.5 | 1.00 | 0.912 | 0.965 | 1.000 | 100.0% | 0.679 |
| Procedural Reasoning | 61 | 24.5 | 1.01 | 0.894 | 0.972 | 0.998 | 100.0% | 0.630 |
| Conditional Reasoning | 74 | 22.3 | 1.02 | 0.905 | 0.988 | 0.985 | 99.0% | 0.641 |
| Comparative Reasoning | 70 | 23.0 | 1.01 | 0.930 | 0.964 | 1.000 | 100.0% | 0.680 |
| Multi-hop Reasoning | 74 | 30.2 | 1.14 | 0.804 | 0.958 | 0.975 | 97.0% | 0.412 |
Appendix figures & tables19 assets
Supplementary material from the paper’s appendix.
Appendix
| Evaluation Criterion | Description | Mean SD |
|---|---|---|
| Correctness | The legal interpretation is factually correct according to the Labour Act. | 4.61 0.54 |
| Faithfulness | All claims are supported by the cited legal evidence without hallucination. | 4.74 0.46 |
| Completeness | The response addresses all important aspects of the user’s query. | 4.52 0.61 |
| Clarity | The explanation is coherent, well-structured, and easy to understand. | 4.67 0.49 |
| Citation Quality | The cited legal provisions are accurate, relevant, and sufficient to justify the conclusions. | 4.79 0.42 |
| Overall Quality | Overall usefulness, reliability, and practical value of the generated legal opinion. | 4.68 0.45 |
| Reasoning Type | Difficulty Level | Sample Size |
|---|---|---|
| Direct Factual Retrieval | Easy | 78 |
| Definitional and Classification | Easy | 76 |
| Procedural Reasoning | Medium | 61 |
| Conditional Reasoning | Medium | 74 |
| Comparative Reasoning | Medium | 70 |
| Multi-hop Reasoning | Hard | 74 |
| Retrieval Strategy | Initial Retrieval Precision | TGLO Rate | Latency (s) |
|---|---|---|---|
| Dense only | 0.52 | 82.3% | 18.2 |
| Dense + BM25 | 0.69 | 91.6% | 21.5 |
| Dense + Link Hops | 0.74 | 96.2% | 25.8 |
| StatuteGraph (Full) | 0.78 | 99.0% | 24.3 |
| Chunking Strategy | Internal Faithfulness |
|---|---|
| Fixed 512 Token | 0.71 |
| Recursive Splitter | 0.76 |
| Whole Chapter | 0.63 |
| Section-only | 0.74 |
| Structure-aware (Ours) | 0.82 |
| Planner Config | Planner-Isolated Precision | Avg Retrieval Rounds | Latency (s) |
|---|---|---|---|
| Static Query | 0.71 | 1.89 | 28.4 |
| Query Rewrite | 0.81 | 1.61 | 26.1 |
| Planner Only | 0.89 | 1.18 | 25.2 |
| Planner + Replanning | 0.91 | 1.05 | 24.3 |
| Max Hop Depth | Internal Faithfulness | Latency (s) |
|---|---|---|
| 0 (no hops) | 0.72 | 22.8 |
| 1 | 0.78 | 23.6 |
| 2 | 0.81 | 25.1 |
| 3 (ours) | 0.82 | 24.3 |
| Configuration | Failed Runs | Recovery Rate (of prior failures) | TGLO Rate | Latency (s) |
|---|---|---|---|---|
| Sequential Pipeline | 71/500 (14.2%) | N/A | 85.8% | 31.2 |
| Supervisor Only | 24/500 (4.8%) | 66.2% (47/71) | 95.2% | 28.1 |
| Supervisor + Retry | 6/500 (1.2%) | 75.0% (18/24) | 98.8% | 25.8 |
| Full Supervisor | 5/500 (1.0%) | 16.7% (1/6) | 99.0% | 24.3 |
| Metric | Aggregate |
|---|---|
| Latency (s) | 24.3 |
| Avg Retrieval Rounds | 1.05 |
| Evidence Coverage | 0.890 |
| Path Completeness | 0.962 |
| Gate-Verified Citation Precision | 0.991 (99.1%) |
| Citation-Checker Pass Rate | 99.2% |
| Question Type | k Ceiling | h Ceiling | Query Ceiling |
|---|---|---|---|
| Direct Factual Retrieval / Definitional & Classification | 5 | 1 | 1 |
| Procedural / Conditional Reasoning | 8 | 2 | 2 |
| Comparative Reasoning | 8 | 2 | 4 |
| Multi-hop Reasoning | 10 | 3 | 4 |
| Hypothetical Legal Reasoning | 8 | 2 | 2 |
| Configuration | Internal Faithfulness | Gate-Verified Citation Precision | TGLO Rate |
|---|---|---|---|
| LabourCrew | 0.82 | 0.991 | 99.0% |
| w/o Trust Auditor | 0.76 | 0.842 | 96.4% |
| w/o Link Hopper | 0.77 | 0.923 | 97.1% |
| w/o Worker Counsel | 0.79 | 0.964 | 98.0% |
| w/o Employer Counsel | 0.81 | 0.978 | 98.6% |
| w/o Legal Interpreter | 0.80 | 0.982 | 98.8% |
| Configuration | Internal Faithfulness | Citation Error Rate | Unsupported Claims % | Gate-Verified Citation Precision |
|---|---|---|---|---|
| No Trust Gate | 0.71 | 0.441 | 8.9% | 0.559 |
| Citation Checker Only | 0.76 | 0.158 | 7.5% | 0.842 |
| Trust Auditor Only | 0.79 | 0.088 | 4.8% | 0.912 |
| Full Trust Gate | 0.82 | 0.009 | 1.2% | 0.991 |
| Configuration | Unsupported Claims % | Internal Faithfulness | Gate-Verified Citation Precision | TGLO Rate |
|---|---|---|---|---|
| Unrestricted Debate-Agent Access | 6.4% | 0.77 | 0.947 | 97.8% |
| Role-Isolated (EEP, ours) | 1.2% | 0.82 | 0.991 | 99.0% |
| Gate Mode | Gate-Verified Citation Precision | Empirical False-Accept Rate | Target α | Guarantee Holds? | TGLO Rate |
|---|---|---|---|---|---|
| Categorical (LLM-decided) | 0.938 | 0.147 | N/A | No | 97.6% |
| Calibrated (CRC, ours) | 0.991 | 0.081 | 0.10 | Yes | 99.0% |
Legal QA
Legal question answering uses language models and legal sources to provide accurate, jurisdiction- and time-specific, verifiable answers.
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