ml4t-model-validation SKILL.md skillA
ml4t-model-validation from ml4t/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add ml4t/skills/ml4t-model-validation@git:20260901.830d7a8Pins git:20260901.830d7a8 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- ml4t/skills
- Path
workflows/model-validation/SKILL.md- Versions recorded
- 5
- Latest version
- git:20260901.830d7a8, committed Sep 1, 2026
- First version recorded
- Sep 1, 2026
- Size
- 5,485 bytes
- Repository stars
- 41
- License
- Apache-2.0
Multi-gate model validation from cross-validation through stress testing to deployment sign-off. Use when qualifying a model for production use.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Model Validation Workflow
A model that passes a single train/test split proves nothing. Rigorous validation requires combinatorial CV, overfitting probability, deflated statistics, feature attribution, and out-of-time holdout - all before any backtest.
## The Problem
A researcher splits data 80/20, trains a model, sees good test-set performance, and runs a backtest. The backtest looks promising. They deploy. The strategy loses money immediately. The cause: the single split was lucky, the model memorized regime-specific patterns, and hyperparameter tuning leaked information across the boundary. Without multiple validation gates, a model that looks good on one split can be arbitrarily overfit.
## The Pattern
### WRONG
```python
# Single train/test split, no overfitting checks, straight to deployment
from sklearn.model_selection import train_test_split
import lightgbm as lgb
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, shuffle=True)
model = lgb.LGBMRegressor().fit(X_train, y_train)
score = model.score(X_test, y_test)
print(f"R2: {score:.3f}") # 0.15 - good enough, deploy
```
### CORRECT
```python
import numpy as np
import lightgbm as lgb
…Read the whole file at its exact version.
How to install
mdr add ml4t/skills/ml4t-model-validation@sha256:1a4e3ab8dd7e09e7The line at the top of this page pins the label git:20260901.830d7a8, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_6rcincnj2oy5dxrj)
1 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 5 versions of this file, all committed on Sep 1, 2026.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260901.830d7a8 latest | 2026-09-01 | 830d7a8 | 5,485 B | A | view · diff |
| git:20260901.11976fe | 2026-09-01 | 11976fe | 5,446 B | A | view · diff |
| git:20260901.7d7c020 | 2026-09-01 | 7d7c020 | 5,424 B | A | view · diff |
| git:20260901.297789f | 2026-09-01 | 297789f | 5,423 B | A | view · diff |
| git:20260901.2c5ab85 | 2026-09-01 | 2c5ab85 | 5,361 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (5485 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
ml4t/skills · 41 stars · license Apache-2.0 · pushed 2026-11-08 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_6rcincnj2oy5dxrj GET https://markdownregistry.com/api/v1/resolve?ref=ml4t/skills/ml4t-model-validation GET https://markdownregistry.com/api/v1/blob/1a4e3ab8dd7e09e739176093ace141d9db97f7b78865fe3caab958f6b354fc05
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.