capability-creator

Trains and evaluates LoRA capability adapters on Qwen3.5-4B through multi-stage SFT, OPD, and GRPO pipelines.

4|1|Updated Apr 13, 2026
One-click install
npx skills add https://github.com/ericflo/kiln --skill capability-creator-ericflo
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: capability-creator
Source: https://github.com/ericflo/kiln/tree/main/.agents/skills/capability-creator
Command: npx skills add https://github.com/ericflo/kiln --skill capability-creator-ericflo

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) components.

What problem does it solve? Improving a deployed language model on a specific capability normally requires ad-hoc scripts, unverified training runs, and evals that can be gamed. This Skill provides a disciplined autonomous loop that uplifts a measurable capability on Qwen3.5-4B served by Kiln, chaining SFT, OPD, GRPO, and agentic-GRPO stages into a pipeline where every iteration is gated by a blind eval and a falsifiable hypothesis. ## Core Features & Use Cases - Method routing by evidence: Analyzes per-sub-score headroom and routes each stage to SFT, OPD, GRPO, or agentic-GRPO based on baseline score, teacher availability, and reward variance rather than a-priori commitment. - Blind-eval discipline: Enforces an information firewall so training never sees eval task pools, with rubric calibration sanity checks (good/bad margin > 0.2) required before any GPU work. - Stage pipeline with promotion gates: Reference stage runners, 3-seed paired evals, adapter verification, cross-capability regression checks, and closeout criteria before a pipeline is marked shipped. - Use Case: Ask the agent to "train a JSON-schema-following capability" and it scaffolds the capability directory, writes an adversarially-designed rubric, baselines the model, runs stage-1 SFT, then routes subsequent stages until headroom is exhausted. ## Quick Start Ask the agent to train a new capability on the kiln-served model, giving it a plain-English description of the capability and confirming a blind eval oracle exists.

Frequently Asked Questions about capability-creator

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I train a new capability on Qwen3.5-4B with Kiln?

Scaffold a capability directory, write capability.md and rubric.py, populate calibration fixtures, and run the baseline eval. Then use headroom analysis and the method router to pick a stage-1 method and execute the matching run_stage script.

When should I use SFT vs GRPO vs OPD for model training?

Use SFT when baseline is below 0.3 or format headroom dominates, OPD when baseline is 0.4-0.8 with a live teacher available, and GRPO when baseline is 0.6-0.9 with a verifier and reward variance above 0.05. Agentic-GRPO applies to multi-turn tool-calling tasks.

Why does GRPO training show all-zero rewards?

All-zero rewards mean every rollout in a group scores 0, so dynamic sampling drops all groups and no gradient signal exists. Either the rubric is too strict or the base model cannot attempt the task, in which case an SFT bootstrap stage should run first.

Can this skill run OPD when the baseline score is above 0.8?

No, OPD at baseline above 0.80 with variable rollout quality risks catastrophic regression because reverse-KL amplifies confidence in malformed samples. The recommended path is SFT on teacher rollouts or accepting the baseline as the ceiling.

What are the limitations of the capability-creator workflow?

It requires a blind eval oracle and does not modify Kiln source, run distillation, edit sibling capabilities, or change the base model. It is also unsuitable for single-shot ablations without a falsifiable hypothesis or for building training datasets from scratch.