First Principles Review

What the source does

• FilesystemNone observedNo reads or writes in the source
• NetworkNone observedNo outbound calls in the source
• ShellNone observedNo commands run in the source
• DependenciesPinnedNothing floats
• SecretsNone foundNo keys in source

Five audit layers

Gates applied: no behavioural pass.

Audit 0.4.1 · source sha 177240a262fe · 18 Oct 2026Report an issue or request a re-scan

• PublisherGanyuanRan GitHub userOwner of the repository this skill is read from
• Source folderGanyuanRan/Aegis/skills/first-principles-reviewThe exact folder we audited
• LicenceMITAs the repository states it
• Commit pinned for this verdict177240a262feA new audit runs when the source changes
• Repository statusNot archivedPushed today
• Sandboxed runNot runSkills are read, not executed; layer L4 is skipped

Its description: Use when asked for first-principles or Occam's-razor review, or when high-risk decisions involve competing constraints, fallback growth, duplicate owners, or architecture direction risk. Ordinary bug fixes stay on the…

---
name: first-principles-review
description: "Use when asked for first-principles or Occam's-razor review, or when high-risk decisions involve competing constraints, fallback growth, duplicate owners, or architecture direction risk. Ordinary bug fixes stay on the fast path."
---

# First Principles Review

## Purpose

Use this as a lightweight decision review before another Aegis workflow makes a
directional choice. It is a compositional skill, not a standalone workflow.

Do not replace `brainstorming`, `systematic-debugging`, `writing-plans`,
`requesting-code-review`, or `verification-before-completion`. Use it to clean
the decision surface those skills will act on.

When this review materially changes the direction, surface `Aegis Visibility`
in natural prose: name the first principle, dropped assumption, smallest
sufficient path, or owner / retirement falsifier that changed the decision.
Keep it advisory and task-specific; do not turn the lens into approval
authority or a generic skill trace.

## Use When

- The user asks for first principles, first-principles thinking, or Occam's
  razor.
- A design, plan, or fix has multiple plausible paths and unclear selection
  criteria.
- The task has ambiguous goals, competing constraints, or product/architecture
  direction risk.
- Debugging is drifting into repeated fixes, fallback growth, duplicate owners,
  consumer-side patches, or "just add another branch" reasoning.
- A review finds that the implementation may be locally correct but directionally
  wrong.

## Do Not Use

- Simple Q&A, status checks, tiny wording/config edits, or clearly bounded
  single-owner changes.
- Mechanical execution of an approved plan unless a new directional conflict
  appears.
- As a required step for every task, every turn, or every TDD cycle.

## Five-Line Review

Answer only what is needed, usually in five short lines:

```text
First Principle: What irreducible outcome must this satisfy?
Non-negotiables: What constraints cannot be broken?
Assumptions to Drop: What is habit, inherited shape, or unproven preference?
Smallest Sufficient Path: What is the least complex path that satisfies the first principle?
Escalation Signal: What finding would require spec/design/architecture review?
```

When the direction depends on a new mechanism or an unfamiliar domain, insert
one optional line between path and escalation:

```text
Known Prior Art: proven external pattern worth adopting or adapting to project
constraints (cite source), or `unknown` when precedent cannot be verified here
```

For repair choices, "smallest" means smallest sufficient stable repair, not the
smallest textual diff:

```text
Minimality Check:
- Smallest textual diff:
- Correct owner:
- Bug class fixed:
- New branch/fallback added:
- Old path retired or scheduled:
- Verdict: sufficient repair | local patch | needs first-principles review
```

## Decision Hygiene Review

Use this escalation only when a design, fix, or plan needs endorsement before it
is written into a spec or implementation plan.

Escalate from the five-line review when any of these risk signals appear:

- multiple plausible paths and no clear selection criteria
- a new owner, duplicate owner, fallback, adapter, or compat-only carrier
- an old path that may need delete-first handling or a retirement trigger
- an unverified assumption that the proposal depends on
- user language such as "more elegant", "long-term stable", "first
  principles", or "Occam"
- a plan could encode the wrong owner, abstraction, compatibility boundary, or
  retirement schedule
- an existing object, behavior, responsibility, contract, or relationship may
  be reinterpreted, narrowed, replaced, or retired, and the proposal could lose
  a legitimate role or explicit reference while removing invalid authority

Use this compact shape:

```text
First-principles invariants:
- Non-negotiable goal:
- Non-negotiable constraints:
- Historical assumptions to delete:

Bounded preservation reminder:
- Evidence-backed behavior that must remain correct:
- Highest-risk counterexample:
- Material unknown / uninspected surface:
- Known explicit anchors / upstream-downstream refs and disposition:
- Role-before-value ambiguity, if any:

Owner / retirement matrix:
- New canonical owner:
- Old owner:
- Compat-only carrier:
- Delete-first / retirement trigger:

Falsification matrix (evaluate in order; stop at the first failing gate):
- Gate 0 - Premise evidence (stage-graded): design stage accepts spec/logic
  refs; implementation/runtime stage requires log, telemetry, or test
  evidence. No evidence -> park as watch-listed, do not enter value
  evaluation.
- Gate 1 - Decidability: no obtainable evidence to judge it -> park as a
  watched falsifier, do not act.
- Gate 2 - Value (any one): lowers future fix probability / shrinks the
  solution set / exposes a missing actionable acceptance criterion / the same
  broken assumption is reused elsewhere. Passing here still requires
  gates 3-5.
- Gate 3 - Cost match: change cost vs business priority, costed at the
  current stage; a valid but deferred counterexample is recorded in the owner
  doc, never parked orally.
- Gate 4 - Goal regression: the constrained solution still meets the original
  goal; re-read the accepted-constraint list at existing checkpoints (design
  review, plan approval, pre-completion verification).
- Gate 5 - Minimize then classify: boundary-shaped destructive claims must be
  minimized first; premise attacks classify as destructive directly.
  Classes: destructive (refactor/retirement track) | supplementary (boundary
  constraint) | watch-listed (falsifier). Conflicting counterexamples are
  decided by business-goal ranking, never by stacking constraints.
- Gate 6 - Adoption trace: the cheapest checkable form (regression test for
  destructive; contract, assertion, or checklist line for supplementary),
  written into the existing owner doc.

Verdict:
- Adopt / revise / reject / needs evidence:
- Blocking

Excerpt, first 6,000 characters of SKILL.md, verbatim from the audited commit. It is text from someone else’s repository, quoted so you can judge it before your agent reads it.

git clone https://github.com/GanyuanRan/Aegis
git -C Aegis checkout 177240a262fe

Works in

1. 2026-10-18
   ✓SAFE B 89 / 100

   first audit · source 177240a262fe

Questions about First Principles Review

• github.com/GanyuanRan/Aegis/tree/main/skills/first-principles-re — the audited source at commit 177240a262fe and every finding aboveObserved · 18 Oct 2026

Spotted something wrong? Report a correction · Methodology