assertion-density SKILL.md skillA
assertion-density from amey-thakur/ai-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add amey-thakur/ai-skills/assertion-density@git:20260728.fac4544Pins git:20260728.fac4544 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- amey-thakur/ai-skills
- Path
skills/code-quality/assertion-density/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260728.fac4544, committed Jul 28, 2026
- First version recorded
- Jul 18, 2026
- Size
- 2,657 bytes
- Repository stars
- 14
- License
- MIT
Place assertions where invariants are established or must hold: constructors, public boundaries, and loop bodies. Use when hardening code whose silent violations would otherwise surface far from their cause.
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
# Assertion density An assertion is an executable claim about what must be true at a point in the program, and its worth is proximity: it fails at the cause, not three stack frames later where the bad value finally breaks something. Scattering asserts at random adds noise; placing them where invariants actually live turns a class of debugging sessions into one clear failure. The skill is knowing those places. ## Method 1. **Assert preconditions at every public boundary.** At the top of an exported function, check the arguments the caller must honor: `assert n >= 0`, non-null, index in range. A caller's mistake becomes a message at the door. 2. **Establish class invariants in the constructor.** After construction, assert the object sits in a legal state: `assert self.balance >= 0`, both ends of a range ordered. An object that cannot exist badly never spreads a bad state. 3. **Guard the loop invariant inside the loop.** Assert the property the loop maintains each pass: an index stays in bounds, a running sum stays non-negative, a heap stays ordered. The assert catches the pass that breaks it. …
Read the whole file at its exact version.
How to install
mdr add amey-thakur/ai-skills/assertion-density@sha256:a32a5b751905a69cThe line at the top of this page pins the label git:20260728.fac4544, 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_re43jyurz4ohxvpw)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between Jul 18, 2026 and Jul 28, 2026, about one every 10 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260728.fac4544 latest | 2026-07-28 | fac4544 | 2,657 B | A | view · diff |
| git:20260718.7c1285c | 2026-07-18 | 7c1285c | 2,647 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 (2657 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
amey-thakur/ai-skills · 14 stars · license MIT · pushed 2026-09-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_re43jyurz4ohxvpw GET https://markdownregistry.com/api/v1/resolve?ref=amey-thakur/ai-skills/assertion-density GET https://markdownregistry.com/api/v1/blob/a32a5b751905a69cc2bd3600105a7ff4bccacbc6c056d7166e99c59b97fab404
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.