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 hamzabellouch/agent-skills --skill kinematic-definitions-reference-framesgit clone --depth 1 https://github.com/hamzabellouch/agent-skillsWrote 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/hamzabellouch/agent-skills/kinematic-definitions-reference-frames)<a href="https://agentmods.dev/skills/hamzabellouch/agent-skills/kinematic-definitions-reference-frames"><img src="https://agentmods.dev/badge/skills/hamzabellouch/agent-skills/kinematic-definitions-reference-frames/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/hamzabellouch/agent-skills/kinematic-definitions-reference-frames"><img src="https://agentmods.dev/badge/skills/hamzabellouch/agent-skills/kinematic-definitions-reference-frames.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 | $0.00037 | $0.00369 |
| Opus 5.5 | $0.00015 | $0.00148 |
| Sonnet 5.5 | $0.00007 | $0.00074 |
| Haiku 4.5 | $0.00004 | $0.00037 |
Grade A, and why
kinematic-definitions-reference-frames 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.
What it actually says
Kinematic Definitions and Reference Frames
ID: mech.kinematics.definitions
Domain: Mechanics → Kinematics
Difficulty: 1/5
Prerequisites
- math.calculus.derivatives
- math.vectors.basics
Core Concepts
- position vector
- displacement
- average vs instantaneous velocity
- acceleration
- reference frame
- frame transformation
Key Equations
$$ \vec v = \frac{d\vec r}{dt} $$ $$ \vec a = \frac{d\vec v}{dt} $$ $$ \vec r_{P/A} = \vec r_{P/B} + \vec r_{B/A} $$
Methods
- Differentiate position to obtain velocity and acceleration
- Integrate acceleration with initial conditions
- Pick the frame that makes the description simplest
Typical Problem Types
- Given x(t), find v(t), a(t) and turning points
- Convert between two moving reference frames
Common Pitfalls
- Confusing speed with velocity
- Treating acceleration as a scalar
- Mixing labels in relative-frame equations
Related Skills
- mech.kinematics.constant_acceleration
- mech.dynamics.newton_laws
References
- Kleppner & Kolenkow Ch.1
- Halliday-Resnick-Walker Ch.2-4
What ships with it
1 file 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.
- 7d ago First seen · 61 lines · 37 tokens per session scan A 0ce5e4a363b2
kinematic-definitions-reference-frames is a skill published in the GitHub repository hamzabellouch/agent-skills (8 stars, last pushed today), licensed MIT. It adds 37 tokens to every session and 369 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 2026-10-10.
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