why SKILL.md skillA

why from painhardcore/pstack is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned

mdr add painhardcore/pstack/why@git:20260827.04830a9

Pins git:20260827.04830a9 in mdr.lock. Pin the fingerprint instead.

Audit grade: A, 17 of 17 checks passed
Kind: SKILL.md skill
Repository: painhardcore/pstack
Path: .opencode/skills/why/SKILL.md
Versions recorded: 1
Latest version: git:20260827.04830a9, committed Aug 27, 2026
Size: 20,858 bytes
Repository stars: 12
License: MIT

Use for 'why does X work this way', 'why we picked Y', design rationale, regressions, postmortems, or data-backed thresholds. Discovers available MCPs and queries each evidence category (source control, issue tracker, long-form docs, real-time chat, infrastructure observability, error tracking, product analytics warehouse) in parallel, then returns a cited read on decisions and tradeoffs. Use how for runtime behavior.

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

# Why

Investigate the motivation and intent behind code. Why was it built this way? What edge cases were considered? What product, business, or operational constraints shaped the design? What alternatives were rejected, and why?

Companion to the `how` skill. `how` answers what the code does and how it works. `why` answers what forces led to its shape.

## How this skill works

Historical context spreads across seven evidence categories: source control history, issue or ticket tracking, long-form documents, real-time team chat, infrastructure observability, error or exception tracking, and product analytics warehouses. You cannot predict from the question alone which one holds the answer, so the skill enumerates available MCPs at run time, maps each to a category, queries all seven in parallel, then synthesizes with explicit confidence calibration. Null results from searched categories are first-class evidence about how the decision was made; report them alongside positive findings. The default is coverage, not minimalism.

## Operating Posture
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint

mdr add painhardcore/pstack/why@sha256:663b1ccaaeaa355d

The line at the top of this page pins the label git:20260827.04830a9, 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](https://markdownregistry.com/badge/art_fyv6qoeebppnruvc.svg)](https://markdownregistry.com/a/art_fyv6qoeebppnruvc)

1 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 1 version of this file, committed on Aug 27, 2026.

version	committed	commit	size	audit
git:20260827.04830a9 latest	2026-08-27	04830a9	20,858 B	A	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 (20858 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

painhardcore/pstack · 12 stars · license MIT · pushed 2026-10-16 · branch master

API

GET https://markdownregistry.com/api/v1/artifacts/art_fyv6qoeebppnruvc
GET https://markdownregistry.com/api/v1/resolve?ref=painhardcore/pstack/why
GET https://markdownregistry.com/api/v1/blob/663b1ccaaeaa355d6bc41c06e3161d8d3b6ac630043bfba5cdf54a3c48da01d1

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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