Skip to the content.

Two Signals for Harness RSI: Verifiable Outcomes and Personal Preferences

Contact Me


In Towards Harness RSI, I discussed how an agent system can keep adapting its harness as models, tools, skills, and conditions change. Feedback helps the system decide what to change and whether the change improves its work.

But feedback comes in different forms. Some tasks provide a clear result: a math answer is correct, a program passes a test, or a player wins a game. Other tasks depend on something the system cannot directly observe: what this user prefers, how they want the agent to work, and what makes a result useful to them.

Harness RSI needs to improve both task performance and its understanding of the individual user. A personal agent can complete a task correctly and still leave its user repeatedly asking for a different tone, level of detail, or way of working.

When the Target Is Verifiable

Reinforcement learning from verifiable rewards, or RLVR, gives a model a reward based on an outcome that can be checked. The DeepSeek-R1 paper describes accuracy rewards for tasks such as math problems and coding problems with executable checks. These settings provide a concrete basis for training: the system can try an answer and receive evidence about whether it satisfies the verifier.

A harness improvement loop can use similar evidence without changing model weights. It might compare two tool workflows by completion rate, test results, latency, or cost. The target is already defined; the experiment asks which workflow reaches it more reliably or efficiently.

Suppose a coding agent repeatedly misses an edge case. A regression test exposes the problem. The harness can revise its investigation or validation procedure, then compare the revised version with the current one on fresh executions. There is an observable criterion for deciding whether the candidate helps.

The signal is strong within the verifier’s coverage. Passing a test suite does not establish that the entire issue is fixed, and a correct final answer does not establish that the user received a useful explanation. Even a clear score is evidence about a defined part of the goal.

When the Target Depends on the User

Now consider writing. Two drafts can both be accurate and grammatically sound. One is formal and detailed; the other is warm and direct. Which is better?

The answer depends on the user, audience, and purpose. There is no universal score that tells a personal agent which draft this user will prefer today. Similar differences appear in how an agent works: whether it explains each step, asks questions early, takes initiative, or presents a compact result for review.

Human preference learning already exists in model training. RLHF uses human feedback to guide model behavior. For example, InstructGPT used human comparisons of outputs to train a reward model, then used that reward model for reinforcement learning. That provides a useful starting point for following instructions and producing responses people prefer under the training setup.

A personal agent has an additional problem: it must learn the preferences of one particular user through ongoing interaction. A generally preferred response may still be poorly suited to that person. The evidence is often sparse, indirect, and mixed with other information in the conversation.

For harness RSI, this creates a second kind of improvement target. The system must discover what better means for this user while improving how it delivers that result.

Dimension Verifiable outcome signals Personal preference signals
Main question Did the result meet a defined criterion? Did the result suit this user in this context?
Examples Correct answer, passing tests, winning a game Tone, detail, structure, initiative, workflow
Evaluation Apply an available verifier Interpret instructions, corrections, choices, and reactions
Main uncertainty Whether the verifier covers the actual goal What the feedback means and how broadly it applies
Harness change Improve task execution and validation Improve user context, instructions, and working procedures

These signals can appear in the same task. A coding change may pass every check, yet its review explanation may be too long for the user. A writing task may have subjective style preferences alongside an explicit, verifiable word limit. The distinction concerns the evidence available, rather than a strict division between domains.

Personal preferences are the main example here, but the same idea extends to learning how to fit a setting or role. The same user may prefer detailed explanations at a desk, brief spoken responses while driving, and suggestions adapted to their immediate surroundings while traveling. An agent working as a company employee might learn team communication conventions and when colleagues expect it to escalate a decision. An agent acting as a waiter might learn when guests welcome attention and when they prefer space. Each setting combines explicit requirements with expectations that emerge through feedback. Harness RSI can use those signals to improve its fit to the role, just as a personal agent learns to better serve an individual user.

Mining Preferences From Interaction

The user rarely supplies a complete preference profile before the agent starts. The agent has to learn from the interaction itself.

An explicit instruction provides direct evidence: “Use a friendly tone” or “Start with the decision.” A correction provides evidence tied to a particular result: “This is too formal” or “Remove the background explanation.” Edits and choices can be informative too. If the user repeatedly chooses a concise draft over a detailed one for status reports, the agent has a reason to investigate a preference for concise status reports.

Other reactions are harder to interpret. “Great” may express satisfaction with the main result without endorsing every aspect of the response. Frustration may come from a wrong answer, excessive delay, or an unwanted workflow. Continued conversation may indicate interest, correction, or new scope. Silence leaves the outcome unknown.

Calling these weak signals describes uncertainty in the evidence. It does not mean that every personal preference is weak. An explicit instruction can be clear and actionable even when the underlying preference is subjective.

User evidence Possible interpretation Limit on the inference
“Keep future status reports short” A stated preference for concise status reports Does not establish a preference for short tutorials
“This sounds too formal” The current draft’s tone is unsuitable The desired replacement tone may still be unclear
Repeated selection of shorter drafts Evidence for concision in comparable writing tasks Audience or task differences may explain the choices
“Thanks, this works” Positive feedback about the result Does not identify which features the user valued
No reply No observed feedback Does not establish acceptance

The useful output of signal mining is a supported, scoped hypothesis. “Prefers concise status reports” retains more meaning than “likes short answers.” It should remain connected to the evidence that produced it, so later feedback can correct it.

Product Design Can Make Hidden Preferences Easier to Observe

An improvement loop can learn from the feedback users happen to provide. Product design can also create natural opportunities for users to reveal their intent and preferences as they work. A concrete suggestion gives the user something to accept or revise, making their choice easier to interpret than a general reaction to a long response.

For example, Codex’s composer predictions suggest a next message. The user can press Tab to insert the suggestion, edit it, and then send it. Accepting the prediction does not send it automatically. This interaction could provide useful evidence for a harness improvement loop: sending the suggestion unchanged supports its fit to the user’s immediate intent, while edits before sending reveal where the prediction needed to change.

The interpretation still has limits. A user may accept a suggestion because it saves typing, and an ignored suggestion may simply have gone unnoticed. A single acceptance does not establish a lasting preference. The useful evidence is the suggestion, its context, and what the user ultimately chose to send. This is a possible use of the interaction for RSI, rather than a claim that Codex currently uses these actions for personal harness improvement.

The broader design opportunity is to make feedback a small, useful part of ordinary work. Users can reveal preferences by choosing, editing, or confirming concrete options, without having to write a separate explanation of everything they want. Harness RSI can then use those observations to form and test better supported preference hypotheses.

From a Reaction to a Harness Change

The repository retrospective loop already treats user replies as evidence about whether a result served their intent. Personal preference learning extends that idea across interactions. The following is a proposed design, rather than a report of measured results.

task result + user response
            |
            v
interpret the feedback in its task context
            |
            v
form a preference hypothesis with evidence and scope
            |
            v
propose a bounded harness change
            |
            v
observe later comparable tasks and user feedback
            |
            v
retain, refine, or reverse the change

Consider a user who repeatedly removes long introductions from project updates. The retrospective first checks what those edits mean. Did the agent repeat information the audience already knew? Did it misunderstand the requested format? Or does the user generally prefer project updates to lead with the decision?

Suppose the evidence supports the last interpretation. A candidate harness change could add a scoped instruction: for this user’s project updates, state the decision first and include background only when it helps the reader act. This changes an instruction or writing procedure; it does not require training new model weights.

The proposal should make a prediction: later project updates will need fewer edits to their openings while preserving necessary context and accuracy. Historical edits motivate the hypothesis. Fresh outputs and subsequent feedback provide evidence about whether the changed harness actually helps.

Fewer corrections are useful evidence, but they are not sufficient alone. The user may stop correcting an agent they no longer trust. When evidence is ambiguous and the distinction matters, a brief question or a comparison of two drafts can help clarify the preference. The system should keep uncertainty visible rather than turn every reaction into a permanent rule.

Preserve Context and Correctability

Preferences have scope. A user may want concise updates and detailed technical explanations, friendly personal messages and formal client proposals. A request for one draft can be a local instruction rather than a durable preference. Preferences can also change over time.

A useful preference record therefore retains the task context, original evidence, confidence in the interpretation, and whether the preference was explicitly stated or inferred. The user must be able to correct or remove it. New explicit instructions should guide the current task when an older inferred preference conflicts with them.

The goal is better service to the user’s intent. Positive reactions should not become an incentive to agree with incorrect claims or omit inconvenient facts. Preference adaptation still needs to preserve correctness and the requirements of the task. A preferred tone cannot compensate for a false answer.

Improving the Signal-Mining Process Itself

The recursive part becomes concrete when the harness also improves how it learns preferences. Its retrospective may notice that it generalizes too far from single corrections, confuses new requirements with dissatisfaction, or keeps asking questions the user has already answered.

Those patterns can motivate changes to the feedback interpretation procedure, the context stored with preferences, or the way relevant preferences are retrieved. Evaluation should ask whether the revised procedure produces better supported interpretations and reduces recurring mismatches. Extracting more preferences is not itself evidence of improvement.

Verifiable outcomes and personal preferences give harness RSI complementary directions. One provides evidence about performance against defined criteria. The other helps the system discover and serve a particular user’s expectations. A personal agent needs both: the ability to do the work well, and the ability to learn what doing it well means for the person it serves.