ml4t-feature-validation SKILL.md skillA

ml4t-feature-validation from ml4t/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned
mdr add ml4t/skills/ml4t-feature-validation@git:20260901.11976fe

Pins git:20260901.11976fe in mdr.lock. Pin the fingerprint instead.

Audit grade
A, 17 of 17 checks passed
Kind
SKILL.md skill
Repository
ml4t/skills
Path
features/feature-validation/SKILL.md
Versions recorded
5
Latest version
git:20260901.11976fe, committed Sep 1, 2026
First version recorded
Sep 1, 2026
Size
5,074 bytes
Repository stars
41
License
Apache-2.0

Validate features before training - IC significance, stability, redundancy, and contamination checks. Use when auditing feature quality before model fitting.

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

# Feature Validation

A feature with IC of 0.05 on the full sample may have IC of 0.12 in one year and -0.03 in every other year. Without validation, the model trains on noise disguised as signal.

## The Problem

Skipping feature validation leads to three failures: lookahead contamination,
regime-specific features that fail live, and redundant features that waste model capacity.

## The Pattern

### WRONG
```python
from sklearn.ensemble import GradientBoostingRegressor

# Train on all features without any validation - overfitting guaranteed
model = GradientBoostingRegressor(n_estimators=200)
model.fit(X_train, y_train)  # 50 features, no idea which are noise
```

### CORRECT
```python
from scipy.stats import spearmanr
import numpy as np

def validate_feature(feature: np.ndarray, target: np.ndarray, dates: np.ndarray) -> dict:
    """Screen a single feature for predictive quality."""
    ok = ~np.isnan(feature) & ~np.isnan(target)  # both: one nan makes ic nan
    ic, p_value = spearmanr(feature[ok], target[ok])
    quarters = dates.astype("datetime64[M]").astype(int) // 3  # numpy has no [Q]
    quarterly_ics = []
    for q in np.unique(quarters):
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint
mdr add ml4t/skills/ml4t-feature-validation@sha256:694fde05b2eaa08d

The line at the top of this page pins the label git:20260901.11976fe, 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.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_qm6an6jcqhliinfr.svg)](https://markdownregistry.com/a/art_qm6an6jcqhliinfr)

2 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.

versioncommittedcommitsizeaudit
git:20260901.11976fe latest2026-09-01 11976fe 5,074 BA view · diff
git:20260901.7d7c0202026-09-01 7d7c020 5,066 BA view · diff
git:20260901.297789f2026-09-01 297789f 5,005 BA view · diff
git:20260901.14ceba92026-09-01 14ceba9 4,694 BA view · diff
git:20260901.c415df02026-09-01 c415df0 4,558 BA view

Audit of the latest version

A  17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (5074 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

GitHub

ml4t/skills · 41 stars · license Apache-2.0 · pushed 2026-11-08 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_qm6an6jcqhliinfr
GET https://markdownregistry.com/api/v1/resolve?ref=ml4t/skills/ml4t-feature-validation
GET https://markdownregistry.com/api/v1/blob/694fde05b2eaa08d533a9d5cc3470c32e567fdcd804c57f879cae8bc93fd6aec

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.

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