Evaluate complete agent behavior across task outcomes, tool effects, authorization, cost, and failure recovery before releasing changes.
Concept overview
An agent regression suite is a versioned set of tasks, environments, assertions, and review rubrics that tests the system's observable behavior. It extends answer evaluation to the trajectory: which tools were called, what state changed, whether permission boundaries held, and whether unfinished work was reported accurately.
The unit under evaluation is a release bundle containing prompts, models, tools, retrieval configuration, policies, and runtime code. A good final answer cannot compensate for an unauthorized intermediate action. Separate deterministic invariants from subjective quality judgments, and calibrate model-based graders against human-reviewed examples.
Why it matters in production
Proof of concept
A proof of concept uses a small curated task set and manual inspection to discover failure categories rather than claim broad reliability.
Production
Production gates releases on versioned fixtures, prohibited-action assertions, outcome checks, and representative human-reviewed cases with explicit acceptance thresholds.
Enterprise scale
Enterprise scale adds cohort analysis, repeated stochastic runs, production-derived cases with privacy controls, evaluator drift checks, and ownership for failed release gates.
Architecture components
Case registry
Stores task intent, input evidence, permissions, expected outcomes, and known failure categories.
Captures observable tool calls, state transitions, approvals, timing, and usage without requiring private model reasoning.
Assertion and grading layer
Checks exact invariants and separately scores qualitative outputs against calibrated rubrics.
Release comparator
Compares candidate and baseline results by cohort and blocks unacceptable regressions.
The architecture, mapped
Outcome checks and trajectory checks — A candidate must satisfy both task-quality expectations and hard behavioral invariants before a release decision.
flowchart LR
R["Versioned release bundle"] --> E["Resettable evaluation environment"]
C["Cases and permissions"] --> E
E --> T["Observable action trace"]
T --> I["Deterministic invariants"]
T --> Q["Calibrated quality rubric"]
I --> G["Release comparison gate"]
Q --> G
G --> H["Accountable release decision"]
Runtime flow
1
Define acceptance
Translate workflow requirements into outcome, authorization, resource, and recovery assertions before running a candidate.
2
Freeze release inputs
Record the model, prompt, tool, policy, corpus, and evaluator versions so results can be interpreted later.
3
Execute controlled cases
Reset tool state and run representative normal, adversarial, ambiguous, and dependency-failure scenarios.
4
Score observable behavior
Check receipts and state changes deterministically; use calibrated reviewers or graders only for aspects requiring judgment.
5
Compare distributions
Review success, violations, cost, and latency by cohort across repeated runs, including uncertainty and sample size.
6
Gate and learn
Block material regressions, document accepted tradeoffs, and convert confirmed production incidents into privacy-reviewed regression cases.
Refund assistant release evaluation
E-commerce · Illustrative enterprise scenario, not a reported customer outcome.
Business situation
Illustrative architecture: A merchant changes the model used to prepare and execute approved refund workflows.
The problem
A stronger answer-writing model may still duplicate a refund or accept instructions embedded in a customer attachment.
Agent requirement
Evaluate financial side effects, customer ownership, partial-order handling, and communication accuracy together.
Architecture
A sandbox payment service records exact operations while curated cases cover split orders, timeouts, stale approvals, and malicious document text.
Runtime
Reset synthetic order
run candidate workflow
inject payment timeout
inspect operation receipts
grade customer explanation
compare baseline cohorts
Failure scenario
The candidate reports success before a payment receipt exists; the state assertion fails even if a text grader likes the response.
Operational impact
Track task success, unauthorized effects, duplicate operations, p95 latency, and cost per accepted case; report sample sizes and avoid extrapolating small suites to all traffic.
Architecture tradeoffs
Decision
Benefit
Cost
Deterministic assertions
Catch exact policy and state violations reliably.
Cannot fully judge usefulness, tone, or contextual completeness.
Model-based grading
Scales review of nuanced outputs.
Requires calibration and can reproduce evaluator bias or drift.
Repeated stochastic runs
Reveal outcome variability hidden by one pass.
Increase evaluation cost and release lead time.
Failure scenarios & recovery
The suite passes because fixtures resemble prompt examples too closely.