justnnc/justnnc-skills
Agent skills for software work that has to be right, not just plausible: prove a tool on a contained copy, fan out a large refactor safely, audit specs against what landed, take a feature idea to a decided design, probe how a codebase works, attack a proposal, and write better skills.
A red-team review of a proposal before it is built or acted on. Use when the user asks for an adversarial, red-team or devil's-advocate review, or when a design, plan, change or analysis is about to be decided and nobody has tried to break it. Not for checking numbers or hunting bugs in a code diff.
A path from a feature idea to a written design document the user has decided. Use when the user wants to explore, scope or specify a new feature, tool or plugin, asks "does this already exist?" or "should we build this?" before building it, or asks for a spec or design doc for something not yet built. Not for implementing or planning the build of a feature already designed, auditing a spec against built code, reviewing a finished plan, or a single decision that needs no research.
A cited, read-only explanation of how a mechanism in a codebase works. Use when the user asks "how does X work in this code", "where is Y computed", "walk me through Z", or wants a reference implementation read to compare with their own, in a large or unfamiliar codebase. Not for a file or function already known (just read it), bug hunting or debugging, reviewing a diff, or changing code.
A fan-out of one large mechanical code change across parallel subagents. Use when a refactor, rename, migration or API move touches hundreds of call sites across many files, when the user asks to split a change per file or component or hand it to several agents at once, or asks how big a change is and whether it is mechanical. Not for edits inside one file, a redesign whose target shape is not yet decided, or a change small enough to make serially.
Execution proof that a script or tool works. Use when about to trust a new or changed script, hook, migration or release tool, and always for anything that rewrites git history, publishes or pushes, deletes, or transforms data; also when the user asks "does this actually work", "test this script", "prove it" or "try it on a copy first". Not for reviewing code by reading it, for writing unit tests of a library, or for fixing the faults found.
A craft checklist for agent skills. Use when the user asks to write, improve, review, test or tighten a skill, a SKILL.md, an agent definition or a reusable brief, or asks why an agent skips, misreads or never triggers a skill. Not for the subject matter of a skill, only how it is written.
A read-only audit of a project's specs against the work that just landed. Use when a batch, feature or set of changes has been merged or is about to be pushed, when the user asks whether a spec is up to date, accurate or drifted from the code, or before a design discussion leans on a spec's text. Not for writing a new spec or design document, reviewing a design document, reviewing code for bugs, or planning work that is not built yet.