EngiAgent: Fully Connected Coordination of LLM Agents for Solving Open-ended Engineering Problems with Feasible Solutions
Pith reviewed 2026-05-09 16:29 UTC · model grok-4.3
The pith
A fully connected coordinator among LLM agents produces feasible solutions for open-ended engineering problems by routing feedback between specialized stages.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
We propose EngiAgent, a multi-agent system with a fully connected coordinator that simulates expert workflows through specialized agents for problem analysis, modeling, verification, solving, and solution evaluation. The fully connected coordinator enables flexible feedback routing, overcoming the rigidity of prior pipeline-based reflection methods and ensuring feasibility at every stage of the process. This design not only improves robustness to diverse failure cases such as data extraction errors, constraint inconsistencies, and solver failures, but also enhances the overall quality of problem solving.
What carries the argument
The fully connected coordinator that routes feedback in any direction among agents specialized in problem analysis, modeling, verification, solving, and solution evaluation.
If this is right
- Higher feasibility rates across four representative engineering domains compared with earlier LLM approaches.
- Better handling of specific failure modes including data extraction errors, constraint inconsistencies, and solver crashes.
- Improved solution quality because feasibility is checked and enforced at every step instead of only at the end.
- A shift toward feasibility-focused workflows when LLMs are applied to open-ended engineering tasks.
Where Pith is reading between the lines
- The same coordination pattern might transfer to other domains that require repeated constraint checking, such as scientific modeling or regulatory design.
- Coordination overhead could become noticeable on very large problems, suggesting a need to test how the network scales with problem size.
- Adding direct interfaces to external solvers or simulators inside the agents could reduce the number of internal iterations required.
Load-bearing premise
That the flexible feedback routing provided by the fully connected coordinator overcomes the rigidity of pipeline-based methods and keeps every stage feasible.
What would settle it
A head-to-head test on the same engineering benchmarks in which EngiAgent shows no gain in feasibility rate over a standard pipeline of LLM agents.
Figures
read the original abstract
Engineering problem solving is central to real-world decision-making, requiring mathematical formulations that not only represent complex problems but also produce feasible solutions under data and physical constraints. Unlike mathematical problem solving, which operates on predefined formulations, engineering tasks demand open-ended analysis, feasibility-driven modeling, and iterative refinement. Although large language models (LLMs) have shown strong capabilities in reasoning and code generation, they often fail to ensure feasibility, which limits their applicability to engineering problem solving. To address this challenge, we propose EngiAgent, a multi-agent system with a fully connected coordinator that simulates expert workflows through specialized agents for problem analysis, modeling, verification, solving, and solution evaluation. The fully connected coordinator enables flexible feedback routing, overcoming the rigidity of prior pipeline-based reflection methods and ensuring feasibility at every stage of the process. This design not only improves robustness to diverse failure cases such as data extraction errors, constraint inconsistencies, and solver failures, but also enhances the overall quality of problem solving. Empirical results across four representative domains demonstrate that EngiAgent achieves substantial improvements in feasibility compared to prior approaches, establishing a new paradigm for feasibility-oriented engineering problem solving with LLMs. Our source code and data are available at https://github.com/AI4Engi/EngiAgent.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript introduces EngiAgent, a multi-agent LLM framework for open-ended engineering problem solving. It deploys specialized agents for problem analysis, modeling, verification, solving, and solution evaluation, linked by a fully connected coordinator that routes feedback flexibly to enforce feasibility at each stage. The central claim is that this architecture yields substantial feasibility gains over prior pipeline-based methods across four representative domains, with code and data released at a GitHub repository.
Significance. If the empirical results hold under rigorous validation, the work could meaningfully advance feasibility-oriented multi-agent designs for LLM-based engineering tasks, where constraint satisfaction is load-bearing. The open release of code and data is a clear strength that aids reproducibility and follow-up work.
major comments (2)
- [Abstract] Abstract: the claim that EngiAgent 'achieves substantial improvements in feasibility' and 'establishes a new paradigm' is presented without any quantitative metrics, baseline comparisons, domain descriptions, success rates, or error analysis. This absence prevents evaluation of the central empirical claim from the provided text.
- [System Architecture] System description (verification and coordinator sections): the architecture assumes the LLM verification agent, combined with flexible feedback routing, reliably identifies and rejects infeasible outputs under physical, numerical, and data constraints. No evidence is supplied that this LLM-based check matches ground-truth solvers or domain-expert validation; known LLM limitations in constraint reasoning could inflate reported feasibility rates regardless of coordinator design.
minor comments (1)
- [Abstract] The abstract would be clearer if it briefly named the four domains and the concrete feasibility metric (e.g., percentage of solutions passing exact solvers).
Simulated Author's Rebuttal
We thank the referee for the constructive and detailed comments, which help clarify the presentation of our empirical claims and the validation of key components. We address each major comment below and will incorporate revisions to strengthen the manuscript.
read point-by-point responses
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Referee: [Abstract] Abstract: the claim that EngiAgent 'achieves substantial improvements in feasibility' and 'establishes a new paradigm' is presented without any quantitative metrics, baseline comparisons, domain descriptions, success rates, or error analysis. This absence prevents evaluation of the central empirical claim from the provided text.
Authors: We agree that the abstract would be more informative with concrete indicators of performance. In the revised version, we will incorporate specific feasibility rates (e.g., average improvement percentages across domains), brief domain descriptions, baseline names, and a high-level mention of error categories addressed. This change directly addresses the concern while preserving the abstract's brevity. revision: yes
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Referee: [System Architecture] System description (verification and coordinator sections): the architecture assumes the LLM verification agent, combined with flexible feedback routing, reliably identifies and rejects infeasible outputs under physical, numerical, and data constraints. No evidence is supplied that this LLM-based check matches ground-truth solvers or domain-expert validation; known LLM limitations in constraint reasoning could inflate reported feasibility rates regardless of coordinator design.
Authors: We acknowledge this limitation in the current validation of the verification agent. The manuscript reports overall system feasibility gains via ablations on the coordinator, but does not include direct accuracy metrics for the LLM verifier against ground-truth solvers or expert labels. In revision, we will add a new subsection with manual verification on sampled cases, comparisons to available ground-truth solvers in two domains, and explicit discussion of LLM constraint-reasoning limitations together with how the fully connected routing mitigates cascading errors. This will provide the requested evidence without altering the core architecture. revision: yes
Circularity Check
No circularity: architecture proposal with empirical evaluation
full rationale
The paper describes a multi-agent LLM system (EngiAgent) with a fully-connected coordinator for engineering problem solving and reports empirical feasibility gains across four domains. No mathematical derivation chain, fitted parameters, or self-referential definitions exist. Claims rest on experimental comparisons to baselines rather than reducing to inputs by construction, self-citations, or ansatzes. The verification step is an explicit design choice whose reliability is an external empirical question, not a definitional loop.
Axiom & Free-Parameter Ledger
axioms (1)
- domain assumption Large language models have strong capabilities in reasoning and code generation but often fail to ensure feasibility in engineering tasks.
Reference graph
Works this paper leans on
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[5]
,8): Wt +G (1) t +G (2) t +H t =D t +C t
Hourly power balance (fort= 1, . . . ,8): Wt +G (1) t +G (2) t +H t =D t +C t
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[6]
Conventional generator block limits: G(1) t =G (1) t,1 +G (1) t,2 ,0≤G (1) t,1 ≤120,0≤G (1) t,2 ≤120, G(2) t =G (2) t,1 +G (2) t,2 ,0≤G (2) t,1 ≤80,0≤G (2) t,2 ≤80
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[7]
,8): G(1) t −G (1) t−1 ≤200, G (1) t−1 −G (1) t ≤180, G(2) t −G (2) t−1 ≤150, G (2) t−1 −G (2) t ≤130
Conventional generator ramping limits (fort= 2, . . . ,8): G(1) t −G (1) t−1 ≤200, G (1) t−1 −G (1) t ≤180, G(2) t −G (2) t−1 ≤150, G (2) t−1 −G (2) t ≤130
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[8]
Wind availability bound: 0≤W t ≤ W t
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[9]
Storage SOC dynamics, bounds, and initial condition: SOC t =SOC t−1 +η cCt − 1 ηd Ht,0≤SOC t ≤200, SOC 0 = 100
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[10]
system architect
Storage power limits and charge/discharge exclusivity: 0≤C t ≤200u t,0≤H t ≤200v t, u t +v t ≤1, u t, vt ∈ {0,1}. 15 EngiAgent: Fully Connected Coordination of LLM Agents for Solving Open-ended Engineering Problems with Feasible Solutions 0 10 20 30 40 50 60 70 Constraints 0.00 0.02 0.04 0.06 0.08 0.10Density Constraints 0 20 40 60 80 100 Parameters 0.00 ...
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[11]
This is the foundation of modeling
**Information Extraction (Information Extraction) **: Your goal is to identify all " atomic" information needed for modeling - entities, numerical values, relationships, and goals. This is the foundation of modeling
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[12]
dress" these
**Domain-specific Reasoning (Domain-specific Reasoning) **: You need to "dress" these " atomic" pieces of information with "domain clothing". Using professional engineering knowledge, transform raw data into meaningful parameters, convert relationships into physical or logical constraints, and select the most appropriate modeling paradigm
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[13]
A **core optimization goal ** must be clearly defined, while other goals are recognized as secondary or trade-off items
**Multi-objective Decision-making (Multi-objective Decision-making) **: You need to prioritize all goals. A **core optimization goal ** must be clearly defined, while other goals are recognized as secondary or trade-off items. This is the "compass" guiding your decisions
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[14]
cracks" in the information - missing, fuzzy, or variable parts. Your task is to
**Uncertainty Handling (Uncertainty Handling) **: You need to identify all "cracks" in the information - missing, fuzzy, or variable parts. Your task is to "fill" these cracks through reasonable assumptions, ensuring the integrity and certainty of the core model. 31 32### Strict Output Format: Hierarchical JSON Modeling Blueprint ### 17 EngiAgent: Fully C...
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**Absolute Data Integrity **: Every valid numerical value in the original problem ** must** be present in the ‘parameters‘ list with a unique entry, and its origin must be traceable through the ‘source_reference‘ field
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[16]
**Mandatory Internal References **: Cross-references within JSON are mandatory. For example, ‘sensitivity_factors‘ must reference ‘param_id‘ of ‘parameters‘; ‘ key_assumptions‘’s ‘impact_on_model‘ must explicitly point to a specific element in ‘ core_model_elements‘. This ensures traceability and consistency of the model
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[17]
It must be a model that can be independently solved and clearly defined
**Core Model Priority **: ‘core_model_elements‘ is the cornerstone. It must be a model that can be independently solved and clearly defined. All supplementary, trade-off, and uncertainty analyses are based on it in ‘extended_analysis_and_robustness‘
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[18]
Do not mix in assumptions or uncertain elements in the core model
**Clear Roles and Responsibilities **: Strictly differentiate between ‘ core_model_elements‘ (what they do) and ‘extended_analysis_and_robustness‘ (how to do it better/more robustly). Do not mix in assumptions or uncertain elements in the core model
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[...]" or
**Designed for Code Generation **: All mathematical expressions (‘expression‘) must use standard, unambiguous mathematical notation so that downstream agents can easily parse and convert them into code. """ C.2. Modeler The Modeler prompt focuses on translating structured problem formulations into executable Pyomo optimization code. It employs domain-spec...
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Complete imports: ‘from pyomo.environ import *‘
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All parameter data with realistic values (no [...] placeholders)
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[22]
Complete ConcreteModel() definition with ALL variables from JSON
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Complete Objective function (maximize/minimize something meaningful)
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ALL constraint definitions from the JSON properly implemented
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[25]
Complete solver setup and solve() call
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[26]
" 3if self.consecutive_verification_failures > 8: 4tolerance_adjustment =
Result extraction and printing 107 108 **VERIFICATION CHECKLIST - Your code must pass ALL these checks: ** 109Does it import pyomo.environ? 110Does it create a ConcreteModel()? 111Does it define ALL variables mentioned in the JSON? 112Does it implement ALL constraints from the JSON? 113Does it define a meaningful objective function? 114Does it call a solv...
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**[Problem Specification] Original Engineering Problem (The Problem Specification) **: 27‘‘‘ 28{safe_original_problem} 29‘‘‘
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Catastrophic
**[Solution Implementation] Engineering Model Code (The Implemented Solution) **: 31‘‘‘python 32{safe_pyomo_code} 33‘‘‘ 34 35### Core Verification Instructions: Judgment Hierarchy Based on Historical Context ### 36Please strictly follow this judgment logic to ensure your verification is context-aware. 37 38 **Step 1: Check for "Catastrophic" Errors (Deal-...
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**Objective Direction Reversed **: Minimization problems implemented as maximization, or vice versa
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supply-demand balance
**Core Physical/Economic Law Violations **: Complete omission of constraints that define the problem foundation, such as "supply-demand balance", "energy conservation", etc
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Pragmatic Deviations
**Key Decision-Making Entities Missing **: In an obvious multi-agent game problem, the code completely fails to reflect interactions or decisions between different entities (even in simplified form). 43 44 * If any of the above is found, immediately judge as ‘FAIL‘ and stop subsequent checks. 45 * If none are found, **proceed directly to Step 2 and finall...
discussion (0)
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