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 ericrisco/rsc-harness --skill motion-craftgit clone --depth 1 https://github.com/ericrisco/rsc-harnessWrote 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/motion-craft)<a href="https://agentmods.dev/skills/ericrisco/rsc-harness/motion-craft"><img src="https://agentmods.dev/badge/skills/ericrisco/rsc-harness/motion-craft.svg" alt="Measured on agentmods" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
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 →
- medium Excessive Agency · line 117 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 | $0.00067 | $0.01647 |
| Opus 5 | $0.00034 | $0.00823 |
| Sonnet 5 | $0.00013 | $0.00329 |
| Haiku 4.5 | $0.00007 | $0.00165 |
Grade A, and why
motion-craft 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 4d 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 — 126 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Motion craft — movement that reads as intent
Motion is not decoration laid over an interface. It is the interface explaining what just happened: what appeared, what it came from, what is still loading, what the user just did. When motion feels wrong the complaint is almost never "the curve is off" — it is "this feels cheap", or "slow", or "I don't know what happened". Those are the symptoms this skill exists to convert into decisions.
The one rule
Every animation answers a question the user is already asking. If you cannot name the question, delete the animation — it is costing time and attention and returning nothing.
| The user is asking | The motion that answers it |
|---|---|
| "Where did this come from?" | It enters from its origin, not from nowhere |
| "Is it working?" | Immediate feedback, under 100ms, even before the result |
| "What did I just do?" | The changed thing moves; nothing else does |
| "Where did it go?" | It exits toward where it can be found again |
| nothing | no animation |
That table is the whole method. Everything below is how to honour it without shipping something that janks.
Duration: the only numbers worth memorising
Movement is read as slow long before it is read as long. The usable range is narrower than most people expect, and the mistake is almost always too slow, not too fast.
| What moves | Range | Why |
|---|---|---|
| State on an element already on screen (hover, toggle, press) | 100–150ms | It must feel like a response, not an event |
| Something entering or leaving in place (menu, tooltip, toast) | 150–250ms | Long enough to be seen, short enough not to be waited for |
| A region rearranging (list reflow, panel) | 250–350ms | Bigger travel needs more time to stay legible |
| A full view transition | 300–400ms | The ceiling. Past 400ms it is a wait, not a transition |
Two rules that come from those numbers, not from taste:
- Exits are faster than entrances, usually by about a third. The user has already decided; making them watch the decision leave is the single most common way an interface feels sluggish.
- Distance and duration scale together, sub-linearly. Doubling the travel does not double the time. If a value grows past 400ms because the element crosses the screen, the layout is the problem, not the timing.
What ships with it
2 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.
- 4d ago First seen · 126 lines · 67 tokens per session scan A 4c867187611d
motion-craft is a skill published in the GitHub repository ericrisco/rsc-harness (70 stars, last pushed today), licensed MIT. It adds 67 tokens to every session and 1,647 once invoked, about $0.0003 per session on Opus 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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