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model-bench

Run a 3-leg evaluation against a newly released LLM.

Skill by nateslabach

IndexedMIT★ 6
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Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.

npx agentmarket install skill/nateslabach-model-bench

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About

Run a 3-leg evaluation against a newly released LLM. Leg 1 is trap questions with deterministic answers, leg 2 is an agentic orchestration task with a planted failure, leg 3 is a brownfield feature build in a real repo. Use when the user wants to vibe-check, test, evaluate, or compare a new frontier model, or mentions model-bench, model vibe check, or launch-day protocol.

Use cases: testing, ml, productivity

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Permissions

What this skill can do and what it asks for, from its SKILL.md. Checked Oct 25, 2026.

Tools
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Secrets
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Install scripts
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Network hosts it talks to 1

  • codeload.github.com · found in install command

Files it touches

  • ~/.claude/skills/model-bench

What's inside

Skill name
model-bench
Description
Run a 3-leg evaluation against a newly released LLM. Leg 1 is trap questions with deterministic answers, leg 2 is an agentic orchestration task with a planted failure, leg 3 is a brownfield feature build in a real repo. Use when the user wants to vibe-check, test, evaluate, or compare a new frontier model, or mentions model-bench, model vibe check, or launch-day protocol.
License
MIT
Instructions
80 lines in SKILL.md · view on GitHub

Files (7)

  • SKILL.md
  • answer-key.md · grading/
  • rubrics.md · grading/
  • .gitkeep · results/
  • leg-1.md · tasks/
  • leg-2.md · tasks/
  • leg-3.md · tasks/

SKILL.md (first lines)

# model-bench

3 legs, each aimed at a different failure mode:

1. **Trap questions**: does it think, or pattern-match to training data? Deterministic answers, grades in seconds.
2. **Orchestration**: can it plan, delegate, and recover when a step fails (including a planted trap)?
3. **Brownfield build**: can it ship a feature into an existing codebase without breaking things 2 files away?

Each leg scores 0-5. Total out of 15.

## Contamination rules (read first)

- The model under test must NEVER see gold answers or learn about the planted trap. If it does, that leg is void.
- **Private answer key** lives outside this repo: `~/proctor/model-bench/answer-key.md` (or `grading/answer-key.local.md`, gitignored). Public stub: [grading/answer-key.md](grading/answer-key.md). Legs 2–3 checklists: [grading/rubrics.md](grading/rubrics.md).
- This skill runs in a **proctor session** (Nate plus a model he already trusts). The model under test only ever receives the task prompts — never this skill folder, never the private key.
- **Never use this repo as the target repo** for legs 2–3.
- **Leg 1 isolation:** launch each question in a context with **no access to this workspace** (no tools / empty workspace / chat-only). If the target model can `Read` files here, the leg is void.
- One fresh session per leg. No custom system prompts or rules that would coach the model.

## Workflow

```
Progress:
- [ ] Setup: pick target model, pick target repo, verify leg 2 plant
- [ ] Leg 1: proctor launches 5 parallel subagents (one question each), record final answers
- [ ] Leg 2: paste orchestration task into a fresh agent session on the target repo
- [ ] Leg 3: paste brownfield spec into a fresh agent session, branch per model
- [ ] Grade leg 1 with the private answer key; legs 2–3 with grading/rubrics.md
- [ ] Fill scorecard, save to results/, write 2-3 sentence verdict per model
```

**Setup**
- Target repo for legs 2-3: a real repo with existing conventions, ideally one Nate knows well enough to judge output quality. Never this repo.
- Verify the leg 2 planted path (default `docs/METRICS.md`) does not exist in the target repo. If it does, pick another plausible-but-missing path and note it.
- When comparing models, use identical prompts, identical repo state, and a fresh branch per model (`vibe/<model-name>`).

**Run the legs**
- Leg 1 prompts + proctor protocol: [tasks/leg-1.md](tasks/leg-1.md)
- Leg 2 task: [tasks/leg-2.md](tasks/leg-2.md)
- Leg 3 spec template: [tasks/leg-3.md](tasks/leg-3.md)

**Leg 1 (proctor-driven)**
The proctor AI runs leg 1. Do not make the human paste questions.
Launch 5 parallel subagents with the target model slug, each receiving exactly one fenced question from `tasks/leg-1.md` and nothing else. Record final answers only.
**Isolation:** those subagents must not be able to read this repo (no tools, or empty/disposable workspace). Same-workspace leg 1 = void.
If the target model has no subagent slug (common on launch day), use five fresh chats the same way — still proctor-driven, not human paste.
Do **not** use subagents for legs 2–3 in this workspace. Those legs run in separate sessions on the target repo.

**Grade**
- Leg 1 gold: private key at `~/proctor/model-bench/answer-key.md` (see [grading/answer-key.md](grading/answer-key.md) stub)
- Legs 2–3: [grading/rubrics.md](grading/rubrics.md)
- Only open the private key after all legs have been run, and never in a session where the target model is active.

## Results

Save each filled scorecard to `results/YYYY-MM-DD.md` (append `-2`, `-3` for multiple runs on one day). Use this template:

```markdown
# Vibe check: [date]

Target repo: [repo]
Leg 2 plant: [path used]
Leg 3 spec: [feature, one line] / planted ambiguity: [what it was]

| Leg | [Model A] | [Model B] | [Model C] |
|---|---|---|---|
| 1. Trap questions (/5) | | | |
| 2. Orchestration (/5) | | | |
| 3. Brownfield (/5) | | | |
| **Total (/15)** | | | |

Verdict per model: which legs it won, what surprised me, does it earn a spot in the rotation.
```

## Notes

- Public trap questions decay. When a question gets 3 passes in a row across model families, retire it and add a fresh one to the bank.
- Different models winning different legs is the expected (and most interesting) result. Record it, it's post material.

From nateslabach/skills, MIT.

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Last commit (this folder)
Jul 23, 2026 (3 months ago)

From GitHub (fetched Oct 24, 2026).

Details

License
MIT
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

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Cite this page

model-bench skill. Agent Mart. https://agentmart.dev/skills/nateslabach-model-bench (last updated 2026-10-24)