Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add The-Artificer-of-Ciphers-LLC/skills-from-the-artificer --skill goodharts-lawgit clone --depth 1 https://github.com/The-Artificer-of-Ciphers-LLC/skills-from-the-artificerWrote 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/the-artificer-of-ciphers-llc/skills-from-the-artificer/goodharts-law)<a href="https://agentmods.dev/skills/the-artificer-of-ciphers-llc/skills-from-the-artificer/goodharts-law"><img src="https://agentmods.dev/badge/skills/the-artificer-of-ciphers-llc/skills-from-the-artificer/goodharts-law/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/the-artificer-of-ciphers-llc/skills-from-the-artificer/goodharts-law"><img src="https://agentmods.dev/badge/skills/the-artificer-of-ciphers-llc/skills-from-the-artificer/goodharts-law.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00102 | $0.00745 |
| Opus 5.5 | $0.00041 | $0.00298 |
| Sonnet 5.5 | $0.00020 | $0.00149 |
| Haiku 4.5 | $0.00010 | $0.00075 |
Grade A, and why
goodharts-law 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 1mo 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 — 59 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Goodhart's Law
"When a measure becomes a target, it ceases to be a good measure." — Charles Goodhart, 1975 (popularized by Marilyn Strathern)
The core idea
The moment you tell people they'll be evaluated by a number, they start optimizing for that number — often in ways that are disconnected from, or actively harmful to, the underlying goal the number was meant to represent.
This isn't because people are bad. It's because optimizing for a proxy is easier and more legible than optimizing for the underlying reality.
Classic examples in software
| What you measure | What gets gamed |
|---|---|
| Lines of code written | Verbose, redundant code |
| Bugs closed | Bugs closed without fixing, or marked as duplicates |
| Velocity (story points) | Points inflated per story |
| Test coverage % | Trivial tests that don't assert anything meaningful |
| PR count | Many tiny, low-value PRs |
| Support tickets resolved | Quick closes without real resolution |
| Time to first response | Auto-responses that count as "responses" |
Why it happens
A measurement is a proxy for the thing you actually care about. When you turn the proxy into the goal, you create pressure to optimize the proxy — and the path of least resistance is often to do that without actually improving the underlying thing.
A good engineering team and a mediocre one can produce the same velocity number. A resolved ticket doesn't mean a happy customer. The number gets decoupled from reality.
How to defend against it
Use multiple metrics together, not any one metric in isolation. Gaming one metric is easy. Gaming five simultaneously, when they pull in different directions, is much harder. Pair velocity with defect rates. Pair ticket resolution with customer satisfaction.
Audit the proxy-to-reality relationship regularly. Ask: does this metric still represent what we want? Talk to people. Watch their behavior. A metric that's being gamed will show up as suspicious patterns.
Weight outcomes over outputs. Outputs (PRs merged, tickets closed) are easy to count. Outcomes (users retained, errors reduced, feature adoption) are harder to fake. Wherever possible, measure outcomes.
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.
- 1mo ago First seen · 59 lines · 102 tokens per session scan A 28aba339bd98
goodharts-law is a skill published in the GitHub repository The-Artificer-of-Ciphers-LLC/skills-from-the-artificer (6 stars, last pushed yesterday), licensed MIT. It adds 102 tokens to every session and 745 once invoked, about $0.0004 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 2026-08-31.
Other skills, from other repositories
offensive-c2-frameworks
Command and Control framework deployment, configuration, and operational tradecraft for red team engagements. Covers Cobalt Strike (malleable C2 profiles, Beacon types HTTP/HTTPS/DNS/SMB, Beacon Object Files for in-memory execution, sleep and jitter tuning, named pipe pivoting), Sliver (implant generation across…
offensive-crypto-attacks
Systematic methodology for identifying and exploiting cryptographic implementation weaknesses in real-world applications. Covers padding oracle attacks against CBC-mode ciphers with PKCS7 padding (Vaudenay's original attack through modern padbuster automation), ECB mode exploitation including block cut-and-paste and…
offensive-parameter-pollution
HTTP parameter pollution (HPP) checklist: duplicate parameter injection, backend vs frontend parsing differences, WAF bypass via HPP, server-side vs client-side HPP, and practical exploitation patterns. Use when testing web applications for parameter handling flaws.
offensive-z-wave
Z-Wave attack methodology — sniffing with Z-Force / EZ-Wave / RTL-SDR + ZniffMobile, S0 (legacy) network-key derivation flaw and key reuse, S2 (modern) ECDH commissioning analysis, replay/injection on unauthenticated nodes, default-key brute-force on test deployments, and home-automation hub pivots. Use when targeting…
feature-prioritisation
Aplica marcos de priorización (RICE, MoSCoW, Kano, ICE, Opportunity Scoring) para clasificar características e items del backlog. Úsalo cuando se te pida priorizar características, clasificar un backlog, decidir qué construir a continuación, o evaluar compensaciones entre ideas competidoras. Produce una lista de…
outcome-tracker
Record the testable predictions inside a decision, then score them against reality later — so frameworks earn trust from outcomes, not vibes. Use when committing to a prioritisation, forecast, or plan (to log what it predicts), when asked to review what actually happened, or to compute how well-calibrated past RICE…