assumption-test SKILL.md skillA

assumption-test from haabe/mycelium is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned
mdr add haabe/mycelium/assumption-test@git:20261011.ead7061

Pins git:20261011.ead7061 in mdr.lock. Pin the fingerprint instead.

Audit grade
A, 17 of 17 checks passed
Kind
SKILL.md skill
Repository
haabe/mycelium
Path
plugins/mycelium/skills/assumption-test/SKILL.md
Versions recorded
16
Latest version
git:20261011.ead7061, committed Oct 11, 2026
First version recorded
May 25, 2026
Size
23,937 bytes
Repository stars
47
License
MIT

Design the smallest viable test to validate or invalidate a critical assumption. Based on Torres's assumption testing framework, organized by Gilad's AFTER model (Assessment → Fact-Finding → Tests → Experiments → Release Results).

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

# Assumption Testing

Every solution rests on assumptions. Test the riskiest ones first with the lightest method possible.

## Preflight: Read target canvas file(s) before any Write/Edit

**Hard rule.** Before issuing `Write` or `Edit` against any `.claude/canvas/*.yml`, use the **Read tool** on that file in this session. Claude Code's Read-before-Write check requires the `Read` tool specifically — `cat`/`head`/`grep` via Bash do NOT satisfy it.

**Edit vs Write — different cost profiles** (verified 2026-05-14):
- **`Edit`** (exact-string replacement): `Read` with `limit: 1` satisfies the check at ~50 tokens. State-tracking is per-file, not per-byte — subsequent `Edit` calls work anywhere in the file. Use this for partial updates against large canvas files (e.g., `purpose.yml` at 800+ lines).
- **`Write`** (full replacement): do a **full Read** first. Write obliterates the file; you should see what you're about to replace. The `limit:1` shortcut is *not* appropriate here.
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint
mdr add haabe/mycelium/assumption-test@sha256:7af731f0f6a90259

The line at the top of this page pins the label git:20261011.ead7061, 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_6346s5j3zdvanotx.svg)](https://markdownregistry.com/a/art_6346s5j3zdvanotx)

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

Versions

The registry has recorded 16 versions of this file, between May 25, 2026 and Oct 11, 2026, about one every 9 days.

versioncommittedcommitsizeaudit
git:20261011.ead7061 latest2026-10-11 ead7061 23,937 BA view · diff
git:20261008.fc240ea2026-10-08 fc240ea 23,567 BA view · diff
git:20261007.33e06562026-10-07 33e0656 23,434 BA view · diff
git:20260926.b711d572026-09-26 b711d57 23,397 BA view · diff
git:20260926.6dc2cad2026-09-26 6dc2cad 23,215 BA view · diff
git:20260926.c3d2b682026-09-26 c3d2b68 22,121 BA view · diff
git:20260926.92bdb912026-09-26 92bdb91 21,894 BA view · diff
git:20260926.e2070662026-09-26 e207066 19,794 BA view · diff
git:20260925.5ce68ce2026-09-25 5ce68ce 19,348 BA view · diff
git:20260915.d0d5b832026-09-15 d0d5b83 18,881 BA view · diff
git:20260909.535cba72026-09-09 535cba7 17,935 BA view · diff
git:20260820.ba431602026-08-20 ba43160 16,972 BA view · diff
git:20260813.418137c2026-08-13 418137c 13,828 BA view · diff
git:20260704.7639f182026-07-04 7639f18 13,199 BA view · diff
git:20260529.ecd6aa32026-05-29 ecd6aa3 13,199 BA view · diff
git:20260525.9fac9422026-05-25 9fac942 12,534 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 (23937 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

haabe/mycelium · 47 stars · license MIT · pushed 2026-10-18 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_6346s5j3zdvanotx
GET https://markdownregistry.com/api/v1/resolve?ref=haabe/mycelium/assumption-test
GET https://markdownregistry.com/api/v1/blob/7af731f0f6a902593020a6eeffa34511aea95b770a68c8faf4e3af76bfe3d6e8

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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