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 ryne2010/harness-engineering-audit --skill product-usabilitygit clone --depth 1 https://github.com/ryne2010/harness-engineering-auditWrote 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/ryne2010/harness-engineering-audit/product-usability)<a href="https://agentmods.dev/skills/ryne2010/harness-engineering-audit/product-usability"><img src="https://agentmods.dev/badge/skills/ryne2010/harness-engineering-audit/product-usability/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/ryne2010/harness-engineering-audit/product-usability"><img src="https://agentmods.dev/badge/skills/ryne2010/harness-engineering-audit/product-usability.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 | $0.00031 | $0.00195 |
| Opus 5.5 | $0.00012 | $0.00078 |
| Sonnet 5.5 | $0.00006 | $0.00039 |
| Haiku 4.5 | $0.00003 | $0.00019 |
Grade A, and why
product-usability 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.
What it actually says
product usability
Follow the repository source-of-truth docs. Do not implement behavior inferred from visual targets unless it is explicit in docs/contracts or approved as an inference. Do not expand product scope, enable real-world effects, use real PII, or weaken tests/invariants.
Workflow
- Read user stories, acceptance criteria, screen contracts, action binding matrix, form lifecycle contracts, and dataflow contracts.
- Inspect visible controls, forms, navigation, workflow states, and persistence expectations.
- Bind every priority control to an action, disabled reason, or unresolved decision.
- Validate happy paths and negative paths for loading, empty, error, permission, and retry states.
- Record evidence, commands run, not-run gaps, unresolved behavior, and remaining risks.
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 · 17 lines · 31 tokens per session scan A 4617372563b5
product-usability is a skill published in the GitHub repository ryne2010/harness-engineering-audit (5 stars, last pushed 1mo ago), licensed MIT. It adds 31 tokens to every session and 195 once invoked, about $0.0001 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 2026-09-05.
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