| name | skill-evolution |
| description | How every skill in the Improve family stays agentic and general instead of rotting into a brittle rulebook. A skill is a measured hypothesis — a few human-owned invariants plus a wide loop-owned judgment surface that improves from outcome data via its own meta-eval. This is the recursion that lets the agent builder learn to build improvable agents. |
Skill Evolution — the skill is a surface, too
A skill written as a fixed checklist is brittle: it can't handle the product nobody anticipated, and it goes stale silently. A skill written as vibes is unaccountable. The resolution is to give every skill the same structure the Improve loop optimizes — a small frozen core and a wide evolvable surface — and then point the loop at the skill itself.
This is the meta-skill. It governs eval-architect, measurement-validation, surface-evolution, and improve-conductor, and it is what makes them general rather than legal-specific (or any-product-specific).
The 4-part contract (every skill in this family follows it)
- Invariant — the 1–2 laws that, if violated, turn the loop into a slot machine. Human-owned. Frozen. Few. ("Gate on held-out." "Score the real deliverable." "Fail loud on incomplete evidence." "Never promote a regression on a guarded dimension.")
- Judgment — what the agent figures out for this product. Loop-owned. Wide. This is the agentic surface — the place the agent is supposed to think, not follow steps.
- Self-test — a checkable signal the agent actually ran to verify it did the work right (the mutation test, CI < delta, diff-the-deployed-surface). Not "I followed the procedure" — a result.
- Evolves-by — the outcome data that updates the judgment surface. Never the invariants.
The split is the answer to "how do you keep it agentic and not a dumb rulebook": few invariants hold the line; judgment is broad and loop-owned; outcomes are measured; the judgment surface self-revises. The agent stays free to solve the novel case — it just cannot violate the handful of laws that make optimization mean anything.
The recursion
Each skill's judgment surface is itself an evolvable surface, optimized by the same loop the skill describes, with a verifiable reward:
Did following this skill produce an eval that yielded real held-out lift, with no critical-dimension regression?
Above a data threshold of real runs, the skill proposes revisions to its own judgment — gated identically (held-out, critical-dimension floor, paired-n ≥ floor, and a footprint-matched placebo — the neutralization gate — that proves the lift came from content, not from added prompt/mount footprint). Invariants are the frozen surface; judgment is the evolvable surface. A skill improving itself is just surface-evolution pointed inward.
The north-star: the agent builder, closed-loop
The agent builder builds agents and the evals that improve them. Its success is not "wrote an eval file." It is the verifiable reward above, applied to the agent it just built:
The eval the builder produced yields real held-out lift on the agent the builder built — no Goodhart regression.
The fleet — legal, tax, gtm, creative, insurance — is the training distribution. Each is {an agent + a known set of gaps}. The builder's score is how much of each gap its produced eval+loop closes on held-out scenarios. The first dogfood data point already exists: legal-agent's loop, repaired in the session that produced these skills, found a transferable jurisdictional-divergence rule and the gate correctly refused to ship it until the evidence was valid — a clean demonstration that the builder's reward must be "real, evidence-backed lift," never "a number went up."
Anti-patterns (the rulebook smells)
- A skill that lists steps but has no self-test — you can't tell if following it worked.
- An "invariant" that's really a judgment call in disguise — over-constraining; it should live in Judgment so the agent can adapt it per product.
- A judgment surface with no evolves-by hook — it will rot, and nothing will notice.
- A reported lift with no held-out or no paired-n, or no footprint-matched placebo (neutralization) — the slot machine. This is the one that ends the product.