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 HK-hub/AgentSkills --skill product-designgit clone --depth 1 https://github.com/HK-hub/AgentSkillsWrote 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/hk-hub/agentskills/product-design)<a href="https://agentmods.dev/skills/hk-hub/agentskills/product-design"><img src="https://agentmods.dev/badge/skills/hk-hub/agentskills/product-design/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/hk-hub/agentskills/product-design"><img src="https://agentmods.dev/badge/skills/hk-hub/agentskills/product-design.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 | $0.00123 | $0.02066 |
| Opus 5.5 | $0.00049 | $0.00826 |
| Sonnet 5.5 | $0.00025 | $0.00413 |
| Haiku 4.5 | $0.00012 | $0.00207 |
Grade A, and why
product-design 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 — 116 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Product Design
Decide what the interface should do, then route who builds and verifies it: pick the right interaction, make scope and consequence clear, cover reality beyond the happy path. This skill owns the decision; it routes the build, verification, and copy out (ownership map in Related skills).
- IS: the decision layer. From a brief, spec, mockup, intent, or existing UI: choose the right interaction and control, name the object, scope, and consequence of actions, enumerate every reachable state, set resilience expectations, require accessibility as task completion. It decides, then routes build and verification out.
- IS NOT:
- building or styling UI, visual direction, palettes, type: use
ui-design. - auditing the built result (rendered quality, a11y markup, keyboard, layout, performance, type surface, React/Next code-level UX with a ship verdict): use
ui-audit. - copy wording, persuasion, or AI-ism removal: use
copywriting. - deep typography or motion: use
typography-auditorui-animation.
- building or styling UI, visual direction, palettes, type: use
product-design or ui-audit?
Dispatch on the artifact, not the topic. Both care about states and interaction; they act at different moments.
| You have... | The question is | Use |
|---|---|---|
| A brief, spec, mockup, intent, or a UI you decide about | What should exist: the right interaction, the action's name, which states should be reachable | product-design |
| Code, a diff, or a running UI you decide on | Is the built result right: states covered, accessible, renders and behaves correctly, ready to ship | ui-audit |
One artifact often needs both in sequence: product-design decides the states that must exist, ui-audit verifies the built code and rendered result implement them. Looking at code or a running screen is ui-audit's turn. This skill reviews the decision and stops at decision altitude; it never writes line-level code fixes.
Operating contract
- Cite a stable rule ID for every finding or non-mechanical decision. Never invent an ID; if none fits, record a coverage gap.
- The project's design system and
AGENTS.mdoutrank this skill's defaults. Defer to them. - Never restyle or rebuild. Decide, then route the build to
ui-design. - One mode per request, resolved from the user's verb before acting.
What ships with it
6 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.
- 1mo ago First seen · 116 lines · 123 tokens per session scan A 90188f21b264
product-design is a skill published in the GitHub repository HK-hub/AgentSkills (6 stars, last pushed 2mo ago), licensed MIT. It adds 123 tokens to every session and 2,066 once invoked, about $0.0005 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 2026-09-03.
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