Pattern guide

Agent evaluation and assurance

Why AI pilots never reach production, and what it takes to get one through the gate.

ways these programmes stall
5
steps in how we would address it
6
questions answered in full
8
In one paragraph

Agent evaluation and assurance is the discipline of proving an agentic system works well enough to deploy, and continuing to prove it once deployed: offline evaluation against a ground-truth set, trajectory scoring of the steps an agent takes rather than only its final answer, online monitoring, and release gates that can actually block a deploy. It is the single most common reason for AI pilots that never reach production. An organisation stuck in pilot usually has a system everybody believes works and no evidence anybody senior is willing to sign, and the gap is between a system that is watched and a system that is measured: monitoring tells you it is running, evaluation tells you whether it is right.

James Rooney, Founder

Updated

Our approach

We have not delivered this at enterprise scale, and here is exactly what we are drawing on

We have built evaluation and confidence scoring into the proofs of concept we have delivered, including validation and scoring of entity-resolution output on a live insurance engagement, and we have recommended against release at least once on every engagement we have run. What we have not yet done is stand up an enterprise-wide agent assurance function across a portfolio of systems, and what follows is the method we would bring to that, not a write-up of a programme we have already run.

So what should you do about it

Keep the assurance function yourselves. Your second line and internal audit should own the gate, because the independence is the whole point of it and it is not something to buy from the firm that built the system. Use us for the build and for designing the evidence, so the ground-truth set, the trajectory scoring, the release criteria and the monitoring arrive as artefacts your own reviewers can hold us to rather than as a report about our work. And if what you actually need is the assurance function itself stood up rather than reasoned about, say so on the call: that is a real piece of work, it is not the piece we have done, and we will tell you whether we are the right firm for it.

Why this matters now

Evaluation has stopped being a research topic and become infrastructure, which tells you where the expectation is heading. The UK AI Security Institute publishes an open-source evaluation framework, Inspect, built around three parts, datasets, solvers and scorers, and ships more than two hundred evaluations inside it. The published work on using a strong model as the judge reports over 80% agreement with human preference, about the level at which humans agree with each other, while naming the position, verbosity and self-enhancement biases you have to design around. The methods exist and are documented. What almost no organisation has is the same rigour pointed at its own workflows, and that gap is where the production decision stalls.

Ask a technical questionanswers from all 12 guides
Ask anything technical about agent evaluation and assurance and I will answer from this guide, and tell you first whether this is work we have delivered or an approach we would be taking.

Prefer to talk it through? Ask us on a discovery call →

Diagnosis

Where these programmes actually stall

Not the risks a vendor lists. The ones that stop the work.

01

Pilot purgatory starts with a demonstration instead of a measurement

Someone senior watched it work and was impressed. That is not an evaluation, and it does not transfer. When the same system is asked to pass a production gate, there is no benchmark, no baseline and no agreed definition of good, so the gate becomes a negotiation rather than a test. Programmes stuck in pilot are almost always stuck precisely here: nobody doubts the system, and nobody can produce the evidence that would let a named person carry the risk of switching it on.

02

Only the final answer is scored

Agents take a sequence of steps: choosing tools, retrieving, deciding when to stop. A system can produce a correct answer through a process that is unsafe, expensive or unrepeatable. Scoring only the output hides that, and it is why systems that tested well fail differently in production.

03

Evaluation is owned by whoever built it

Self-marked homework. Where the build team owns the benchmark, the benchmark tends to describe what the system already does. Assurance needs a separate owner with the standing to block a release, which is an organisational question rather than a tooling one.

04

The pilot succeeded and then went nowhere, because nobody owned what came next

A successful pilot creates an orphan. The sponsor who funded an experiment is rarely the person who will carry a live system, its run cost, its incidents and its audit trail, and in most organisations nobody has been asked to. So a pilot succeeded and then went nowhere is usually not a technical verdict at all: it passed, and there was no named owner, no run budget and no slot in a delivery roadmap to receive it. We treat naming that receiver as part of the pilot rather than as a conversation for afterwards, because the answer changes what is worth building.

05

Nothing watches it after go-live

Model behaviour drifts, retrieval corpora change, and the input distribution moves. Without online monitoring against the same criteria used offline, degradation is discovered by users. Most programmes budget for pre-production evaluation and nothing for the two years afterwards.

Prescription

How we would address it

Grounded in The Tenhaw Way and the engagements written up in our case studies.

  1. 01

    Define what good means before anything is built

    The same discipline as pricing an outcome in currency: if you cannot state the acceptance criteria, you cannot manage the work. We establish the ground-truth set and the pass thresholds with the business owner during design, and they become the release gate rather than a retrospective justification.

  2. 02

    Measure confidence alongside accuracy, and derive it from provenance

    Accuracy and confidence are the two measures we work to, and they answer different questions. On the insurance engagement, confidence was derived from which third-party source the data came from, combined with model certainty and a search-based cross-check, not from the model's self-reported score alone. Provenance-derived confidence is what makes routing defensible, because you can explain to the business owner why a given record was escalated.

  3. 03

    Score the trajectory, not just the answer

    Tool selection, retrieval quality, step count, cost and stopping behaviour are all measured, because a right answer reached the wrong way is a production incident waiting to happen. This mirrors how we treat delivery: flow and process are measured, not just the output at the end.

  4. 04

    Put the gate in someone else's hands, and be willing to be that person

    Assurance sits with a named owner outside the build team, with the authority to hold a release. It is the same accountability mapping as any other consequential decision: who decides, on what evidence, and who can overrule them. Part of what an external partner is for is being the person who can say no without worrying about their next promotion. We have recommended against release at least once on every engagement we have run, usually when a date was being defended rather than a readiness assessment.

  5. 05

    Design the online case to match the offline one

    The criteria that gate the release are the criteria monitored in production, so degradation is comparable rather than anecdotal. Alerting thresholds and the rollback decision are agreed before go-live, not during the first incident.

  6. 06

    Make the evidence the artefact, and name the regime each artefact answers

    Evaluation output is written for the audiences that will ask for it (risk, audit, and the regulator) rather than reconstructed under pressure later. If the evidence is a by-product of the process it is cheap, and if it is assembled retrospectively it is expensive and thin. For a UK insurer it is worth being specific about which regime each artefact is for, because that decides whether the same work gets done once or four times. The model and decision inventory, holding prompts, retrieval corpora, tool permissions and model versions as versioned artefacts with named owners, is what a model risk management framework asks for, and SS1/23 is the UK statement of that expectation for banks; insurers sit outside its formal scope and get asked about it anyway. Outcome measures emitted by the system as it runs, rather than reconstructed from logs a quarter later, are the Consumer Duty evidence for any workflow that touches a customer outcome, because that regime is written around acting to deliver good outcomes for retail customers and monitoring whether you did, rather than around any particular mechanism. Degradation monitoring alongside availability monitoring, and a fallback that is exercised rather than documented, are what an impact tolerance under the operational resilience regime actually rests on. And field-level provenance back to the source document or API is what the data quality expectations under Solvency II and Solvency UK come down to in practice for the actuarial function. One evaluation design can answer all four, but only if it is specified that way at the start.

Accuracy and confidence are the two measures we work to, and they answer different questions.
Where this usually starts

Agentic Design Team

A pair who design the agentic systems, and the infrastructure to run them at scale. £35k–£55k / month · 2–4 months.

What that engagement covers

Agent evaluation and assurance: your questions

Why do AI pilots never reach production?

Most commonly because there was never an evaluation, only a demonstration. Without a ground-truth set, agreed acceptance criteria and a release gate someone outside the build team can hold, the production decision becomes a negotiation with no evidence to settle it, and negotiations without evidence default to no. AI pilots that never reach production tend to share three further properties: only the final answer was scored rather than the agent's trajectory, so nobody knows how it behaves on the cases it has not seen; nothing was designed to monitor it after go-live, so operations cannot say what they would be accepting; and no named person was ever asked to own the live system, its run cost and its incidents. All four are addressable before a line of code is written, and all four are expensive to fix once a pilot has already been declared a success.

What do we do when a pilot succeeded and then went nowhere?

Separate the two questions that are usually tangled together: is it good enough, and who is receiving it. For the first, write the acceptance criteria the business owner would actually sign, then measure the existing system against them honestly. That is a two to three week piece of work and it either produces a gate you can pass or a specific, costed list of what is missing, which is far better than the ambient sense that the pilot was fine. For the second, name the person who will own the live system, its run budget and its incidents, and get them to agree the criteria before you re-test. Pilot purgatory is nearly always the second problem wearing the costume of the first: teams keep improving a system that nobody has been asked to take.

What is trajectory evaluation for AI agents?

Scoring the sequence of steps an agent takes (which tools it chose, what it retrieved, how many steps it used, what it cost, and when it decided to stop) rather than only the final output. It matters because an agent can produce a correct answer through a process that is unsafe, unrepeatable or prohibitively expensive, and output-only scoring makes that invisible until production.

Should a consultancy be willing to recommend against its own release?

Yes, and it is one of the more useful things an external partner is for. An internal team recommending a delay is arguing against a date their own management committed to, with their next promotion in the room. Tenhaw has recommended against release at least once on every engagement it has run, usually where a launch date was being defended rather than a readiness assessment being made. If a supplier has never told you not to ship, that is information about the supplier rather than about your programmes.

What do you measure when there is no ground truth?

Confidence derived from provenance rather than from the model's own certainty score. Where the data came from (which enrichment source, corroborated by an independent search) gives you a defensible basis for routing even before a labelled set exists. It is not a substitute for ground truth and we would still push to build one, but it means an organisation with no appetite for a labelling exercise is not stuck with nothing.

Who should own AI agent evaluation?

Someone outside the team that built the agent, with the standing to block a release. Where the build team owns the benchmark, the benchmark tends to describe what the system already does. This is an accountability question rather than a tooling one, and it is settled during operating-model design by mapping who decides, on what evidence, and who can overrule them.

What should we measure after an agent is live?

The same criteria that gated the release, so degradation is comparable rather than anecdotal, plus cost and latency distributions and the rate at which humans override the agent. Override rate is often the most useful early signal, because it moves before accuracy metrics do and it is measured on real decisions.

What does an evaluation harness for an agent actually consist of?

Four parts, and they are more ordinary than the phrase suggests. A dataset: real cases with the answer a qualified person would accept, held under version control and grown every time something goes wrong in production. A runner that executes the system against every case reproducibly, pinning the model version, the prompts, the retrieval corpus and the tool permissions, because a result you cannot reproduce is an anecdote. Scorers, which are a mixture of exact checks, rule-based assertions and, for open-ended output, a model acting as judge. And a report a non-engineer can read, showing the score against the threshold, what regressed since the last run, and what each run cost and how long it took. The UK AI Security Institute's open-source Inspect framework is built around exactly that shape, datasets, solvers and scorers, which is a reasonable sanity check on any design somebody presents to you. The part people underestimate is the dataset, because it is the only part that cannot be bought.

Sources

Where the checkable claims came from

Every source below was opened and read before it was attached. Where nothing survived that check, the claim on this page was softened rather than given a plausible-looking link.

  1. 01
    UK AI Security Institute, Inspect: a framework for large language model evaluations

    Open-source, built by the UK AI Security Institute and Meridian Labs around datasets, solvers and scorers, with more than 200 evaluations included. Cited here as evidence of the shape a serious harness takes, not as a recommendation of a tool.

  2. 02
    Zheng et al., Judging LLM-as-a-Judge with MT-Bench and Chatbot Arena (2023)

    Source of the over 80% agreement figure, and of the position, verbosity and self-enhancement biases that make a model judge useful for triage and unsafe as a gate.

  3. 03
    FCA, the Consumer Duty

    The Consumer Principle, the cross-cutting rules and the four outcomes, in the regulator's own words. Read it before accepting anyone's account of what the Duty asks of an agent.

  4. 04
    FCA, the Senior Managers and Certification Regime

    The regime behind the claim that accountability resolves to a named individual rather than to a system.

Talk to us about agent evaluation and assurance.

A 30-minute call with James Rooney. We'll tell you honestly which parts of this we have done before and which we would be doing for the first time, and you'll leave with a rough scope either way.

30 minutesWith James personallyNo obligation

Most organisations start with a fixed-price Agent-Readiness Audit · £30k–£90k · 6–8 weeks