Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/ericrisco/rsc-harnessnpx agentmods add skills/ericrisco/rsc-harness/author-skillWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/ericrisco/rsc-harness/author-skill)<a href="https://agentmods.dev/skills/ericrisco/rsc-harness/author-skill"><img src="https://agentmods.dev/badge/skills/ericrisco/rsc-harness/author-skill/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/ericrisco/rsc-harness/author-skill"><img src="https://agentmods.dev/badge/skills/ericrisco/rsc-harness/author-skill.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high Rogue Agent · line 9 Skill modifies its own code, configuration, or behavior at runtime. Self-modification enables an agent to escalate privileges, disable safety constraints, or install persistent backdoors.Fix: Prevent the skill from modifying its own code, SKILL.md, or configuration files. Treat skill files as read-only at runtime.
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00079 | $0.04180 |
| Opus 5.5 | $0.00032 | $0.01672 |
| Sonnet 5.5 | $0.00016 | $0.00836 |
| Haiku 4.5 | $0.00008 | $0.00418 |
Grade A, and why
author-skill scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 19d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 195 lines — stays where its author put it; the contents beside it link to each section on GitHub.
author-skill — write skills that trigger and teach
This is the meta skill: it authors and edits the other skills in the rsc catalog. A skill is two things bolted together — a description that fires at the right moment, and a body that makes the agent better once it fires. Most skills fail on the first. Treat them as two separate engineering problems with two separate quality bars.
Where the SDD chain (specify → plan → … → ship) builds product, author-skill builds the tools that build product. Use it whenever a skill is born or edited.
Not this skill — delegate: a product feature specced or planned → ../specify/SKILL.md, ../plan/SKILL.md. An autonomous agent or tool-calling loop → ../building-agents/SKILL.md. Generic project docs or a wiki article → the ../harness/SKILL.md 02-DOCS engine. Bootstrapping a workspace or profiling the user → ../init/SKILL.md.
Read 02-DOCS/wiki/harness/user-profile.md and speak in the register its technical_level records (technical terms, or plain words with analogies); ../init/SKILL.md sets it, and orient owns the voice. With no profile, use analogies and ask once "technical or with analogies?" — skill authoring is itself a technical act, so a non-technical author needs each convention explained, not just named.
What a skill is (the anatomy)
skills/<id>/
├── SKILL.md the body: frontmatter (name + description + origin) then the prose
├── references/ progressive-disclosure detail, loaded only when the body points to it
│ └── <topic>.md
├── evals/
│ ├── cases.yaml trigger + capability test cases
│ └── README.md how to run the evals, honestly
└── scripts/ optional; verify.sh + helpers for skills with a checkable artifact
└── verify.sh
The frontmatter decides if the skill loads. The body decides how good the agent is once it does.
The description — the single highest-leverage line
The description sits in context on every turn the skill is installed, invoked or not. The body is only paid for when the skill fires; the description is paid for always. So length here is a cost, never a credit. A vague description is a skill that never fires; an over-broad one hijacks unrelated turns. Get this right before anything else.
What ships with it
5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 19d ago Changed c501ceaadcec
- 1mo ago First seen · 195 lines · 79 tokens per session scan A 92641a171fb0
author-skill is a skill published in the GitHub repository ericrisco/rsc-harness (239 stars, last pushed yesterday), licensed MIT. It adds 79 tokens to every session and 4,180 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
writing-skills
Authors new SKILL.md files that conform to the dojo spec.
skill-authoring
Creates and structures SKILL.md files for AI coding agents, including YAML frontmatter, trigger phrases, directive instructions, decision trees, code examples, and verification checklists. Use when the user asks to write a new skill, create a skill file, author agent capabilities, generate skill documentation, or…
skill-creator
A guide for creating and editing reusable instruction packages called skills. A skill gives an agent the knowledge and workflow needed for a particular kind of task.
anchor-and-lock
Consults a check that sits outside the loop system before finalizing any decision the frozen facts bear on, and refuses every attempt by a loop to rewrite a node marked frozen, regardless of how convergent the loop's own reasoning looks.
query-graph
Loads schema.sql into a local SQLite file, then answers availability and provenance questions against the nodes/edges tables with real SQL instead of re-reading source material.
build-subgraph
Traverses a full graph and returns a bounded subgraph around one target node -- its depth-bounded dependencies plus any disputed claims attached to it -- while proving everything else was left out.