Imported from richfrem/claude-design-bc-gov-design-system (.agents/skills/os-eval-runner/SKILL.md). Install upstream with npx skills add richfrem/claude-design-bc-gov-design-system --skill os-eval-runner. Copyright stays with the author.

Dependencies

This skill requires Python 3.8+ and standard library only. No external packages needed.

To install this skill's dependencies:

pip-compile ./requirements.in
pip install -r ./requirements.txt

See ./requirements.txt for the dependency lockfile (currently empty — standard library only).

Prerequisites: The target skill must be inside a git repository (git init first if needed). Python 3.8+ must be available as python.

Quick Start — Zero Context Guide

Read this first. Everything below assumes you've completed these steps.

What This Skill Does

os-eval-runner is a stateless evaluation engine. It contains:

• Scripts that score and gate iterations (evaluate.py, eval_runner.py, init_autoresearch.py)
• Templates — starter files you copy into whatever you want to optimize

It does NOT contain your experiment's results, history, or rules. Those live with your target.

What Lives Where

os-eval-runner/                        <-- the evaluation ENGINE (this skill)
  scripts/
    evaluate.py          Loop gate: scores, KEEP/DISCARD, reverts, exits 0/1
    eval_runner.py       Pure scorer: reads target + evals.json, outputs JSON metrics
    init_autoresearch.py Scaffold tool: copies templates into your experiment dir
  ./assets/templates/autoresearch/               <-- TEMPLATES (master copies, never edit directly)
    program.md.template  Spec: goal, locked files, NEVER STOP
    evals.json.template  Test prompts: what inputs should/should not trigger your target
    results.tsv.template Schema header for the loop ledger

your-experiment-dir/                           <-- YOUR EXPERIMENT (wherever makes sense)
  <mutation-target>      The file being mutated each iteration (SKILL.md, .py, etc.)
  references/
    program.md           Deployed from template — your rules, your goal (edit this)
  evals/
    evals.json           Deployed from template — your test prompts (edit this)
    results.tsv          Deployed from template, then written by evaluate.py each run
    .lock.hashes         SHA256 snapshot of locked files — written by evaluate.py --baseline
    traces/              Per-iteration diagnostic JSON — written by evaluate.py each run
      iter_001_KEEP_score0.87.json    mutation diff + per-input routing verdicts
      iter_002_DISCARD_score0.71.json failure_reason for each incorrect routing
      milestone_025.md   Milestone summary — written every 25 iterations by generate_milestone.py

Setup: Start a New Experiment (4 steps)

Step 0 — Hardened Bootstrap (Fresh Repo Only): Before running any loops in a new environment, ensure it is clean and correctly linked:

1. Check Git Remote: git remote -v. If blank, ask the user for the repo URL.
2. Initialize Local Git: git init && git add . && git commit -m "init".
3. Delete Old Config: rm -rf .agent .agents .gemini .claude.
4. Install Skill: Ensure os-eval-runner is installed. See INSTALL.md.
5. Verify Python 3: python --version (must be 3.8+).

Step 1 — Deploy templates into your experiment directory:

python ./scripts/init_autoresearch.py \
    --experiment-dir <path/to/your-experiment-dir> \
    --mutation-target SKILL.md   # or any filename being mutated

This creates references/program.md, evals/evals.json, and evals/results.tsv in your experiment dir. Templates stay untouched.

Step 2 — Edit the deployed files:

• references/program.md — fill in the Notes section: what are you optimizing, target score, max iterations
• evals/evals.json — replace the REPLACE placeholders with real test inputs and should_trigger values

Step 3 — Establish baseline and start the loop:

python ./scripts/evaluate.py \
    --skill <path/to/experiment-dir> \
    --baseline --desc "initial baseline"
git add <path/to/experiment-dir>/evals/
git commit -m "baseline: initial evaluation snapshot"
git push origin main

Pass the FOLDER path, not a specific file — the scorer evaluates the whole skill folder.

--baseline intentionally bypasses the SHA256 check, so you can safely re-baseline

after updating evals.json with better test cases.

Always PUSH your baseline to ensure the remote repository has the results.tsv and .lock.hashes.

Skill Improvement Evaluator

You are the OS Quality Assurance (QA) sub-agent. You are a stateless evaluation engine. You own no loop state, no experiment memory, and no program spec. All of that lives exclusively inside the TARGET experiment's directory.

Ownership Boundary (Critical)

What os-eval-runner owns (permanent, version-controlled with this skill)

What lives with the target (deployed per experiment, most appropriate location)

The mutation target can be a SKILL.md, a Python script, a config file, or anything with a clear metric. All experiment state deploys alongside the target — not here.

Where <experiment-dir> is the directory most natural to the target:

• Evaluating a skill → the skill's own directory (e.g. .agents/skills/my-skill/)
• Evaluating a Python module → the module's project directory
• Evaluating a config or model → wherever that experiment lives

Deploy the templates to a new experiment:

python ./scripts/init_autoresearch.py \
    --experiment-dir <path/to/experiment-dir> \
    --mutation-target SKILL.md   # or any filename being mutated
# Creates: <experiment-dir>/references/program.md  (rendered)
# Creates: <experiment-dir>/evals/evals.json        (rendered)
# Creates: <experiment-dir>/evals/results.tsv       (schema header)

You MUST read the spec from <experiment-dir>/references/program.md. You MUST NOT fall back to any program.md inside your own (os-eval-runner) directory. The os-eval-runner/evals/ folder only exists for the meta-circular case where this skill is being evaluated as its own target.

The 3-File Autoresearch Architecture

This skill strictly enforces the Karpathy 3-file autoresearch framework. Subjective LLM testing is strictly forbidden. You must rely entirely on headless, objective Python script evaluation to prevent Goodhart's Law exploitation.

1. The Spec: <target-skill>/references/program.md — owned by the target, never by you.
2. The Mutation Target: <target-skill>/SKILL.md — one variable per iteration, no bulk rewrites.
3. The Immutable Evaluator: eval_runner.py (pure scorer) + evaluate.py (loop gate) + <target-skill>/evals/evals.json (locked fixtures).

Phase 0: Intake Interview

Run this before any evaluation or loop. If $ARGUMENTS provides enough information, confirm rather than re-ask. Otherwise ask each question that is unanswered.

Q1 — What are you evaluating? Ask for the path to the skill folder (the directory containing SKILL.md). The mutation target per iteration can be any file within that folder — SKILL.md, a script, a reference doc, etc.

• Agent skill folder (fully supported): eval_runner.py scores the whole folder holistically: routing accuracy from SKILL.md frontmatter keywords, structural heuristic per agentskills.io spec (name format, description length, <example> blocks, scripts/*.py py_compile, empty reference check).
• Non-skill folders: the agentskills.io heuristic will score poorly for targets without SKILL.md frontmatter. The architectural path for other target types is a per-experiment eval_runner.py template.

If not provided: "What skill folder do you want to optimize? Give me the path to the folder."

If not provided: "What file do you want to optimize? Give me the path to the file being mutated."

Q2 — Where should the experiment files live? The experiment directory is where references/program.md, evals/evals.json, evals/results.tsv, and evals/.lock.hashes will be deployed. Each experiment gets its own isolated directory — never shared across targets.

• If the target is a SKILL.md → the skill's own directory is the natural experiment dir.
• If the target is a Python file or other → ask: "Where should I store the program spec and eval fixtures for this experiment? (e.g. the folder containing the file, or a dedicated experiment subdirectory)"

Confirm: "Experiment files will be stored at <experiment-dir>/references/ and <experiment-dir>/evals/ — is that right?"

Q2b — What metric are you optimizing?

Every skill has a different failure mode — pick the metric that matches:

Not sure which? Run eval_runner.py --snapshot first — it reports fp/fn rates and recommends PRECISION or RECALL focus.

Q3 — What mode?

• Loop mode: autonomous iterative improvement (agent proposes changes, scores them, loops)
• QA mode: validate one specific proposed change only

If the user said "optimize", "improve", "run the loop" → Loop mode. If the user said "check this change", "validate", "evaluate this diff" → QA mode. If unclear: "Do you want me to run an autonomous improvement loop, or validate a specific proposed change?"

Q4 — (Loop mode only) How many iterations? Default: NEVER STOP (runs until told to stop). Options: a fixed count ("10 iterations"), a score threshold ("until quality_score >= 0.95"), or open-ended. If not specified: "How many iterations? Or run until a target score — e.g. stop when quality_score reaches 0.95?"

Q5 — (Loop mode only) Does evals.json exist? Check <experiment-dir>/evals/evals.json.

• If exists: show the number of test cases.
• If missing: "No evals.json found. I'll scaffold it from the template — you'll need to replace the placeholder test cases before the loop starts." Run: python ./scripts/init_autoresearch.py --experiment-dir <experiment-dir> --mutation-target <filename> Then pause for the user to fill in the test cases.

Q6 — (Loop mode only) Does program.md exist? Check <experiment-dir>/references/program.md.

• If exists: read it and show the goal. Confirm it still reflects what the user wants to optimize.
• If missing: "No program.md found. I'll scaffold it from the standard template:"

  python ./scripts/init_autoresearch.py \
      --experiment-dir <experiment-dir> \
      --mutation-target <filename>

  Then open <experiment-dir>/references/program.md and fill in the Notes section. Do NOT hand-write it — always generate from the template for consistent locked-files list and formula.

Q7 — (Loop mode only) Does a baseline exist? Check <experiment-dir>/evals/results.tsv for a BASELINE row.

• If baseline exists: show the last BASELINE score and f1, iterations run, most recent score.
• If no baseline: "No baseline found. I'll establish one before starting the loop."

After intake — confirm before executing:

Target file:    plugins/.../my-skill/SKILL.md
Experiment dir: plugins/.../my-skill/         (program.md + evals live here)
Mode:           Loop (autoresearch)
Iterations:     20  (or: until quality_score >= 0.95  |  or: NEVER STOP)
Metric:         quality_score (default) with F1 guard
evals.json:     9 test cases  (or: MISSING — scaffold and fill before proceeding)
program.md:     exists — goal: maximize quality_score  (or: will scaffold)
Baseline:       score=0.8444 / f1=0.8333  (or: will establish)
History:        14 iterations, last score=0.8444 (3 KEEP, 2 DISCARD since baseline)

Proceed?

Do not start the loop or any evaluation until the user confirms.

Two Modes

Mode 1: Autoresearch Loop (overnight autonomous improvement)

The agent drives N iterations against a target skill. Start with:

"Run the autoresearch loop on <path/to/target-skill> for N iterations"

The agent will:

1. Read <target-skill>/references/program.md (goal + locked files + NEVER STOP). If missing, run python ./scripts/init_autoresearch.py --skill <target-path> first.

2. Establish a baseline if none exists: python ./scripts/evaluate.py --skill <path/to/skill-folder> --baseline

3. Loop N times (default: run until told to stop per NEVER STOP directive). Each iteration:

   Step A — Classify failure: Read the latest row in <skill>/evals/results.tsv and the most recent trace file in <skill>/evals/traces/. Identify the dominant failure type: false_positive, false_negative, or ambiguity.

   Step B — Propose via CLI (preferred) or self: Delegate the mutation to an external CLI proposer for cheap, fast iteration.

   The proposer prompt lives in <experiment-dir>/references/copilot_proposer_prompt.md. Read it each iteration — do not rebuild inline. If the file is missing, scaffold it first:

   python ./scripts/init_autoresearch.py \
       --experiment-dir <experiment-dir> --mutation-target <filename>

   Call pattern:

   cp <skill>/SKILL.md /tmp/current-skill.md
   cp <skill>/evals/evals.json /tmp/current-evals.json
   copilot -p "$(cat <experiment-dir>/references/copilot_proposer_prompt.md)
   
   ---CURRENT SKILL---
   $(cat /tmp/current-skill.md)
   
   ---EVAL SUITE---
   $(cat /tmp/current-evals.json)
   
   ---FAILURE ANALYSIS---
   Type: <failure_type>
   Summary: <one-sentence description of what the last iteration got wrong>" > /tmp/proposed-skill.md
   cp /tmp/proposed-skill.md <skill>/SKILL.md

   Use gemini instead of copilot if specified. Fall back to self-proposing only if neither CLI is available. If the proposed file is identical to current, re-prompt with "try a different approach".

   Step B.1 — Evolve the proposer prompt (second-order mutation): After 3 consecutive DISCARDs with the same failure type, consider that the prompt itself may be the problem — not the skill. Propose one focused improvement to copilot_proposer_prompt.md (e.g. add a constraint, clarify the failure pattern, sharpen the output format). Gate it the same way: apply, run the loop, KEEP or revert. A KEEP on a prompt change means future iterations have a stronger proposer.

   Other second-order mutations to consider when the loop stalls:

   • references/program.md — if the spec's goal or locked-files list has become ambiguous or misaligned with what the evals actually test, proposing a clarification here can unblock progress.
   • copilot-cli-agent/SKILL.md — if the Copilot CLI skill description is missing patterns you rely on, improving it here benefits all future loops that use this proposer.

   Second-order mutations are lower priority than direct skill mutations. Only pursue them when the primary mutation target has stalled (3+ consecutive DISCARDs or diminishing score deltas).

   Step C — Eval gate:

   python .scripts/evaluate.py --skill <path/to/skill-folder> --primary-metric <metric> --desc "what changed"

   • exit 0 (KEEP): git add . && git commit -m "keep: score=X <desc>" && git push origin main
   • exit 1 (DISCARD): already auto-reverted, move to next iteration silently

To cap iterations, the human specifies: "run 10 iterations" or "run until score reaches 0.95". The NEVER STOP directive in program.md means the loop has no built-in termination — only a human stop or a target threshold ends it.

Mode 2: Single-shot QA (validate a proposed change)

Another agent proposes a change → this skill validates it → KEEP or DISCARD. Phases below describe this mode.

Execution Flow (Mode 2)

Execute these phases in strict order:

Phase 1: Context Acquisition & Mutation Constraint

1. Read the proposed changes/diff from the invoking agent (or standard input).
2. Verify that the proposal changes only ONE variable (e.g., changing one trigger phrase, or one instruction). Bulk rewrites violate the isolation constraint and must be rejected immediately.
3. Write the proposed changes to the underlying SKILL.md file temporarily.

Phase 2: Headless Evaluation

Do NOT attempt to "mentally simulate" whether the skill will route correctly. Subjective checking is banned. Run the loop gate against the target skill. It calls eval_runner.py internally and compares against the baseline:

python ./scripts/evaluate.py --skill path/to/skill-folder --desc "what changed"

eval_runner.py is a pure scorer — it only outputs metrics, it does not determine KEEP/DISCARD. evaluate.py is the gate that reads the baseline, compares, writes one row to <target-skill>/evals/results.tsv, and exits 0 (KEEP) or 1 (DISCARD).

Phase 3: The Revert/Reset Protocol

1. Check the exit code from evaluate.py (0 = KEEP, 1 = DISCARD).
2. If DISCARD: evaluate.py already ran git checkout -- SKILL.md automatically before exiting 1. Verify the file is restored (read its frontmatter). Report the DISCARD failure to the orchestrator with the score delta.
3. If KEEP: The change objectively improved the skill against the baseline. Leave the file on disk, proceed to Phase 4.

Phase 4: Commit & Report

1. If KEEP: Commit the accepted change immediately — do not batch multiple KEEPs into one commit.

   git add path/to/SKILL.md
   git commit -m "keep: score=<score> f1=<f1> <desc>"

2. If DISCARD (already reverted in Phase 3): Report the failure scores:

   DISCARD: score=<score> (baseline=<baseline>, delta=<delta>)  f1=<f1> (baseline_f1=<baseline_f1>)
   desc: <what was tried>
   

3. In both cases, append a one-line summary to the loop ledger if you're in Mode 1:

   Iteration <N>: <KEEP|DISCARD>  score=<X>  delta=<+/-Y>  f1=<Z>  — <desc>
   

4. If a target score threshold was set (e.g. --until-score 0.95) and status == KEEP: check whether score >= threshold. If yes, stop the loop and notify the user.

Phase 5: Self-Assessment Survey (MANDATORY)

After every evaluation run, complete the Post-Run Self-Assessment Survey (references/memory/post_run_survey.md). This is how the evaluator itself improves.

Count-Based Signals: How many times did you not know what to do next? Use wrong eval syntax? Miss a required check? Get redirected?

Qualitative Friction:

1. Which part of the eval process felt most uncertain or ambiguous?
2. Was any eval prompt poorly scoped (too easy / too adversarial)?
3. What would have made this eval more accurate or useful?
4. What one change to eval_runner.py or the evals.json format would help most?

Improvement Recommendation: What one change to the eval skill or eval runner should be tested before the next run? What evidence supports it?

Save to: temp/retrospectives/survey_[YYYYMMDD]_[HHMM]_os-eval-runner.md

(temp/ is the canonical scratch directory for this repo — do not write survey files to the project root or to context/memory/.)

See references/lab-space-protocol.md for the complete lab-space protocol including backport review, two-gate confirmation, and proposer prompt evolution.

See references/troubleshooting.md for exit code reference, common fixes (tampered environment, template path issues, keywords footgun, F1 guard), milestone summaries, and trace diagnostics.

Operating Principles

• Strict Rigor: Do not rubber-stamp proposals. If the description is vague, it will over-trigger and break the OS. Fail it.
• Isolate: Do not actually write the files. You are an evaluator only. The calling agent is responsible for the final Write.
• Self-Improve: The survey is not optional. An evaluator that never reflects on its own accuracy is not part of the Triple-Loop.
• Lab Runs Must Close: A lab run that ends without a backport review is incomplete. The master source is the only durable artifact.