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 jeremylongworth-source/AgentSkills --skill game-3d-developmentgit clone --depth 1 https://github.com/jeremylongworth-source/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/jeremylongworth-source/agentskills/game-3d-development)<a href="https://agentmods.dev/skills/jeremylongworth-source/agentskills/game-3d-development"><img src="https://agentmods.dev/badge/skills/jeremylongworth-source/agentskills/game-3d-development/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/jeremylongworth-source/agentskills/game-3d-development"><img src="https://agentmods.dev/badge/skills/jeremylongworth-source/agentskills/game-3d-development.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 | $0.00080 | $0.01114 |
| Opus 5 | $0.00040 | $0.00557 |
| Sonnet 5 | $0.00016 | $0.00223 |
| Haiku 4.5 | $0.00008 | $0.00111 |
Grade A, and why
game-3d-development 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 5d 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 — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Game 3D Development
Core Workflow
- Identify the engine/runtime, target device, input methods, camera style, and performance budget before designing the implementation.
- Inspect the existing project patterns first: scene graph ownership, update loop, asset loading, physics layer, animation system, ECS/component conventions, and build tooling.
- Prefer composition for scalable gameplay entities: one script/component has one job, entities "have" capabilities instead of inheriting every behavior from broad base classes, and a small orchestrator coordinates components when needed.
- Prefer proven engine or library primitives for physics, animation, navigation, collision queries, and asset loading. Hand-roll only when the feature is small, intentionally custom, or the project has no suitable dependency.
- Build the smallest playable slice that proves camera, controls, collision, feedback, and failure states together.
- Verify visually and behaviorally. For browser/WebGL projects, use browser screenshots and canvas checks. For engine projects, run the available editor, playmode, unit, or build checks when possible.
Implementation Priorities
- Controls: support the expected input devices, define dead zones and sensitivity, avoid frame-rate dependent movement, and handle focus/pause states.
- Camera: specify follow target, damping, collision avoidance, field of view, occlusion handling, and motion-sickness risks.
- Physics: use fixed-step simulation, clear collision layers, explicit units, stable mass/force values, and predictable trigger behavior.
- Scene architecture: keep spawn/despawn, pooling, asset lifetime, save state, and cross-scene dependencies explicit.
- Component composition: split health, input, movement, attack, interaction, inventory, hurtbox, hitbox, and camera behaviors into reusable components when they can stand alone.
- Animation: define source of truth between animation and gameplay state; avoid hidden animation events for critical game rules unless that is the established pattern.
- Performance: watch draw calls, shader cost, texture memory, skeleton count, physics query volume, allocations in hot loops, and asset streaming stalls.
- Tooling: create debug views, tunable constants, gizmos, or inspector fields when iteration speed matters.
What ships with it
3 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.
- 5d ago First seen · 74 lines · 80 tokens per session scan A 92d718820bc1
game-3d-development is a skill published in the GitHub repository jeremylongworth-source/AgentSkills (1 stars, last pushed 6d ago), licensed MIT. It adds 80 tokens to every session and 1,114 once invoked, about $0.0004 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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