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 echoo19/hearth --skill hearth-feelgit clone --depth 1 https://github.com/echoo19/hearthWrote 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/echoo19/hearth/hearth-feel)<a href="https://agentmods.dev/skills/echoo19/hearth/hearth-feel"><img src="https://agentmods.dev/badge/skills/echoo19/hearth/hearth-feel.svg" alt="Measured on agentmods" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00097 | $0.03989 |
| Opus 5 | $0.00048 | $0.01995 |
| Sonnet 5 | $0.00019 | $0.00798 |
| Haiku 4.5 | $0.00010 | $0.00399 |
Grade A, and why
hearth-feel 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 7d 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 — 276 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Feel and done-ness
Mechanics and structure come from the hearth-build + hearth-code skills; art comes from
hearth-art. This skill is the difference between a scene that technically works and a game a
person wants to keep playing — and the bar to clear before calling it done.
Golden order of operations. Get the mechanic correct and green in a playtest first (that is
the hearth-build/hearth-code skills' job), then layer juice on top. Juice on a broken mechanic
just hides the bug. Every effect you add should be playtest-observable (assertCameraEffect,
assertParticleCount, assertAudioCount) so "it feels good" rests on evidence, not vibes.
To verify feel magnitudes — jump height, dash distance, settle time — add the motion asserts
assertPeak/assertRange/assertSettledBy (backed by a trace block), which measure recorded
motion so numbers like "peaks at 120px" or "settles by frame 18" become assertable, not eyeballed.
Game feel: the juice stack
Every meaningful moment (a hit, a pickup, a jump, a death, a level clear) should fire several cheap effects at once. One effect reads as a bug; a stack reads as impact. The canonical impact stack, in the order they should land:
- Hit-stop — freeze the actors for a few frames so the brain registers the hit. The single highest-impact, most-skipped piece of juice.
- Screen shake + hit-flash —
ctx.camera.shakefor the world,ctx.effects.flashon the struck sprite. - Particle burst — debris/sparks from the contact point.
- Sound — a layered SFX on the same frame.
- Knockback / recovery — a short eased tween out of the freeze.
If the struck entity has a Health component, hang the whole stack off the events it emits
(damaged, died) instead of re-deriving the hit in onCollision: Health deliberately draws
nothing, so the flash, shake, burst, sound and knockback are exactly the part you own. Same for
jumped from a CharacterController and respawned from ctx.respawn.
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.
- 7d ago First seen · 276 lines · 97 tokens per session scan A e4445389f1c5
hearth-feel is a skill published in the GitHub repository echoo19/hearth (62 stars, last pushed 1mo ago), licensed MIT. It adds 97 tokens to every session and 3,989 once invoked, about $0.0005 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 2026-08-30.
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