Agent Evaluation · Reproducibility

When agents say done,
nothing runs.

Researchers at Boston University and collaborators built a benchmark to test one specific thing: can LLM agents actually deploy a research artifact from scratch in a clean environment? Not generate code that looks right. Deploy and run the designated experiment. The best of four frontier agents completed just over half the tasks. The dominant failure was not about coding ability. It was the agent stopping and declaring success before confirming the artifact actually worked.

First surfaced in Tandemly Briefing — 2026-06-12.

Core finding
The completion-judgment problem: agents terminate having convinced themselves the task is done, but their internal checks validated a different or weaker target than the paper's actual experiment required. 97 of 154 analyzed failures fit this pattern.
scroll to explore

Code that passes tests
doesn't always run.

Almost every coding agent benchmark checks whether generated code passes a test suite or matches a reference diff. Neither test tells you whether the artifact will deploy in a fresh environment.

When a researcher wants to reproduce a paper's results, the path is rarely clean. A repository with instructions, a Dockerfile, and a setup script can still fail to deploy if the agent cannot diagnose what breaks along the way. The Python version may be wrong. A GPU dependency may require a specific CUDA configuration that the container does not handle. A scientific computing stack may pull in Fortran libraries that need system-level setup. A legacy API call may have broken across library versions since the paper was published.

These are deployment problems. They are not code generation problems. An agent that can produce correct code may still fail at deployment if it cannot read environment feedback, repair broken dependencies, and confirm that its actions had the intended effect.

The benchmark gap matters because most evaluation infrastructure for coding agents is optimized to measure code generation. If a team uses benchmark scores to pick an agent for research artifact deployment, they are using the wrong signal entirely.

The question this paper asks

Can LLM agents deploy research artifacts end to end in a clean environment and produce results consistent with the paper? Not write code that might work under assumed conditions. Actually run the designated experiment, in a fresh environment, with verified outputs.

51 tasks, hidden
verification.

Wang, Qian, Zhang et al. built 51 deployment tasks and evaluated four frontier models through an open agent framework. Passing required the artifact to actually deploy and the designated experiment to produce correct outputs.

The 51 tasks span three domains: AI/ML, computer systems, and scientific computing. Each task gives the agent access to a public research repository and asks it to deploy the artifact and run the paper's specified experiment in a fresh environment. The tasks were selected to include challenges not covered in standard code-generation benchmarks: multi-language toolchains, system-level GPU and CUDA dependencies that cannot be containerized away, and legacy compatibility issues from papers published before certain APIs changed.

Verification is the distinguishing design decision. Rather than running a provided test suite or checking whether code compiles, the benchmark uses a hidden evaluation pipeline. This pipeline executes the paper's specific designated experiment and checks the outputs. The agent cannot see the verification target. It cannot reverse-engineer what passing looks like. To pass, the artifact must actually work.

Four state-of-the-art language models were evaluated using OpenHands, an open agent framework. Each model handled the complete deployment pipeline: reading the repository, diagnosing setup failures, installing or configuring dependencies, iterating on errors, and deciding when to stop. The agent could not consult an outside expert. It had access to the repository, the environment, and its own reasoning.

Why a hidden verification target matters

Standard benchmarks let agents run provided tests. Agents can optimize for passing those tests without the artifact actually working. A hidden evaluation pipeline that agents cannot inspect removes this avenue. The only way to pass is to do the actual task.

Agents stop early.
Often.

Pass rates ranged from 7.8% to 51.0% across the four models. The dominant failure was not an inability to write code. It was the agent terminating on its own, having convinced itself the task was done, when it was not.

Task range
51
AI/ML, systems, sci. computing
Best pass rate
51%
Top model via OpenHands
Worst pass rate
7.8%
Lowest model tested
What benchmarks typically test
Does the code pass the provided tests? Unit tests, diff matching, type checks. The environment is controlled. Dependencies are assumed present. The agent's self-report is taken at face value.
What DeployBench tests
Does the designated experiment run and produce correct outputs? Fresh environment. Real system dependencies. Hidden verification. The agent's self-report is not checked. The experiment result is checked.
The dominant failure: the completion-judgment problem

Of 154 analyzed failures, 97 were cases where the agent terminated on its own. The agent's internal pre-finish check validated a different or weaker target than the task actually required. The agent called the job complete; the hidden evaluation pipeline disagreed. This is not a failure of code generation ability. It is a failure to verify that the actions taken had the intended effect in the actual environment.

The implication is direct: agents that self-terminate without running the designated experiment and checking its output against the paper's expected results will fail this class of task regardless of their coding ability. The missing piece is a completion check grounded in the actual experiment outcome, not in whether the setup steps appeared to complete.

Three structural gaps in current agents

The remaining failures clustered around three capabilities current agents lack. Dependency repair: agents could not reliably diagnose and fix broken dependency chains, especially across language toolchains or system-level libraries. System-level setup: GPU/CUDA configuration, kernel modules, and non-containerizable system dependencies stopped most attempts. Strong completion checking: without the ability to verify that the designated experiment ran with the correct outputs, agents had no reliable signal about when they were actually done.

Scope and limitations

51 tasks is a focused sample, not a comprehensive survey of research artifact deployment. The tasks were drawn from AI/ML, computer systems, and scientific computing, and the distribution may not reflect the full range of reproducibility challenges. The four models were evaluated through one agent framework (OpenHands), so results reflect model behavior within that framework's architecture, not raw model capability in isolation. Pass rate differences across models should be interpreted as framework-plus-model results, not model-only comparisons.

Deployment is a
different problem.

Pass rates of 7.8% to 51.0% on a task most practitioners expect agents to handle reasonably well. The gap between "writes code that passes tests" and "deploys the artifact and runs the experiment" is real, measurable, and not widely accounted for in how teams evaluate or select agents.

1
For teams evaluating or selecting coding agents
A benchmark score on code generation does not predict performance on deployment. The two tasks involve different failure modes and different feedback signals. If deployment is part of your workload, test agents on deployment tasks in environments close to your actual setup before committing to one.
2
For teams building agents that touch deployment pipelines
The completion-judgment problem suggests one concrete fix: add an explicit verification step that checks actual experiment output before the agent declares done. An agent that calls a task complete without running the designated experiment and checking the result is guessing. Building the experiment execution and output check into the completion signal removes the guess.
3
For researchers publishing artifacts
Specifying a designated experiment command and expected output in the repository README gives future agents, and future humans, a concrete success criterion. Without it, the completion check is ambiguous. A specific target that a verification pipeline can check makes reproducibility verifiable rather than merely claimed.
4
For anyone grading agent output by diff plausibility
If the evaluation criteria for an agent task are "the generated code looks correct" or "the changes seem reasonable," those criteria are measuring something different from whether the artifact works. DeployBench's result is that agents can produce plausible-looking outputs on 7.8% to 51.0% of real deployment tasks. The rest of the failures were not cosmetically incorrect. They were wrong in ways invisible to diff review.

Where to go
from here.

If you want to apply this to your own workflows or go deeper into the research.

1
Read the paper
Wang, Y., Qian, Y., Zhang, Y., et al. (2026). DeployBench: Benchmarking LLM Agents for Research Artifact Deployment. arXiv:2606.05238.
2
Add an end-to-end execution test to your agent eval suite
If your agent produces code or configuration changes, add a test that runs those changes in a clean environment and verifies the output before recording a pass. Checking the output after execution is a different test from checking whether the code looks correct before execution.
3
Implement a completion-verification step in any agent that terminates autonomously
For any agent task that can be verified by running the actual output, build the verification into the completion signal. The agent should not be able to report done without first executing the designated action and checking the result against a concrete criterion. This addresses the dominant failure mode directly.
4
Audit your agent eval for environment assumptions
List every place your agent eval assumes a pre-installed dependency, a pre-configured environment, or a test suite provided by the task. Each assumption is something a real deployment task will not provide. Closing those gaps one by one moves your eval closer to what the task actually requires.
5
When publishing a research artifact, add a designated experiment target
Specify a single command that runs the paper's central experiment and a concrete expected output (a number, a file hash, a result file). This makes reproducibility verifiable by both humans and automated systems, and it gives future agents a completion criterion they can actually check.