Examples

Generates test cases for functions and components. Use when writing tests or creating test suites.

FFmpeg media processing — video/audio conversion, trimming, encoding, filters, streaming. CLI and ffmpeg.wasm patterns.

Token budget tracking and enforcement for Gastown convoy-level execution. Hard limits with pre-execution checking, per-convoy and per-agent tracking, structured stop reasons.

Use when the user asks to forge, scaffold, or author a new cartridge — content cartridge, department cartridge, or chipset bundle. Drives the cartridge-forge loop (scaffold → fill → gate checks → commit) via the skill-creator cartridge CLI.

Calculus, series, numerical methods, and optimization for computational mathematics. Covers limits (epsilon-delta, L'Hopital, squeeze theorem), derivatives (rules, optimization, related rates), integrals (Riemann sums, Fundamental Theorem of Calculus, integration techniques), series (convergence tests, Taylor and Maclaurin expansions), differential equations (separable, linear, exact), numerical methods (Newton-Raphson, Euler method, Simpson's rule), and computational pitfalls (floating-point arithmetic, catastrophic cancellation, numerical stability). Use when computing derivatives, integrals, limits, series, solving differential equations, or analyzing numerical accuracy.

Electromagnetism from Coulomb's law through Maxwell's equations and optics. Covers electric fields, Gauss's law, electric potential, capacitance, DC circuits (Ohm's law, Kirchhoff's laws), magnetic fields and forces, Biot-Savart law, Ampere's law, Faraday's law of induction, Lenz's law, Maxwell's equations in integral and differential forms, electromagnetic waves, the speed of light derivation, and optics (reflection, refraction, lenses, interference, diffraction). Use when analyzing electric or magnetic phenomena, circuit design, wave propagation, or optical systems.

Runtime HAL for multi-runtime agent orchestration. Detects active AI assistant (Claude Code, Codex, Gemini, Cursor) and exposes uniform interface for startup injection, GUPP enforcement, and communication selection.

Upstream version checking, agentskills.io spec compliance audit, Claude Code feature gap analysis. Activates on updates, version checks, or alignment work.

Analyzing and forecasting data ordered in time. Covers stationarity and differencing, autocorrelation (ACF and PACF), AR, MA, ARMA, and ARIMA models, the Box-Jenkins methodology, seasonality and SARIMA, forecasting with prediction intervals, and residual diagnostics including the Ljung-Box test. Use when data is indexed by time, when forecasting future values, when detecting trend or seasonality, or when checking whether residuals still carry structure.

Design and analysis of combinational and sequential digital circuits using Boolean algebra, truth tables, K-maps, CMOS gate implementation, flip-flops, registers, counters, and finite state machines. Covers De Morgan's theorems, canonical sum-of-products and product-of-sums forms, minimization techniques, propagation delay, setup and hold times, metastability, synchronous design discipline, and FSM encoding. Use when designing, minimizing, verifying, or debugging any circuit whose signals take only discrete logic values.

Bench instruments and measurement techniques for electronics — digital multimeter, oscilloscope, logic analyzer, spectrum analyzer, function generator, power supply, and their proper use. Covers probing technique, ground loops, loading effects, trigger modes, FFT mode pitfalls, signal integrity, noise budget analysis, and debugging workflows from "it doesn't work" to "here is the failure mechanism." Use when measuring, debugging, or characterizing any electronic circuit or firmware-hardware interaction.

The discipline of keeping a field notebook — words, pictures, numbers, metadata, and questions captured during sustained outdoor observation. Covers the Laws notebook method, the sit-spot practice, phenology recording, sketch-first-name-later discipline, and the long-term research value of accumulated journals. Use when the task is to teach or structure ongoing field observation rather than answer a one-shot identification.

MLOps and the production ML lifecycle -- model packaging and serving, CI/CD for ML, experiment tracking, model registries, reproducibility, production monitoring for data and concept drift, retraining pipelines, A/B and shadow deployment, and rollback. Covers batch vs online/real-time inference, REST endpoints, feature stores, data and version pinning, deterministic pipelines, performance-decay detection, and retraining triggers. Use when deploying models to production, serving predictions, monitoring for data or concept drift, setting up ML CI/CD, tracking experiments, managing a model registry, or planning retraining, shadow rollout, and rollback.

Design of active analog circuits built around operational amplifiers and discrete gain stages — inverting, non-inverting, difference, and instrumentation topologies, negative feedback and loop stability (gain-bandwidth product, phase margin, compensation), active filters (Sallen-Key, multiple-feedback biquad), sinusoidal and relaxation oscillators, comparators and Schmitt triggers, voltage references (bandgap, shunt, series), and linear versus switching voltage regulators. Covers how to pick a topology, close a feedback loop that stays stable, set gain and bandwidth, and choose a power-conversion approach. Use when designing an amplifier, filter, oscillator, reference, comparator, or regulator, or when reasoning about feedback stability, loop gain, phase margin, or op-amp non-idealities.

Provides best practices for AI agent orchestration including MCP servers, A2A protocol, multi-agent coordination, and swarm architectures. Use when designing agent systems, configuring MCP servers, setting up agent teams, or when user mentions 'MCP', 'A2A', 'agent orchestration', 'multi-agent', 'swarm', 'agent team', 'LangGraph', 'CrewAI', 'AutoGen'.

The history and philosophy of science as a meta-discipline. Covers scientific paradigms and paradigm shifts, the nature of scientific theories versus hypotheses and laws, landmark discoveries as case studies in methodology, creativity and serendipity in science, the social and cultural context of scientific practice, and science-society relationships. Use when teaching, discussing, or evaluating the nature of science, its history, or its place in society.

Distributional analysis of environmental benefits and burdens across communities. Covers the historical origins of environmental justice in the U.S. civil rights tradition, siting and exposure disparities, indigenous rights and land stewardship, climate justice at global and intergenerational scales, procedural vs. distributional vs. recognition justice, and the environmental justice screening tools used by regulators. Use when analyzing who bears environmental harm and who receives environmental benefit, or when designing interventions whose distributional consequences matter.

Persist progress for long-running jobs (batched LLM calls, large ingestions, multi-hour syncs) so that a context reset, crash, or interrupt doesn't lose work. Use whenever a job iterates over N items and completing item K matters independently. Provides a resumable.mjs library pattern plus the skill's invocation heuristics.

Yoga practice with an emphasis on alignment, props, and staged progression as the Iyengar lineage teaches it, alongside enough context about the broader lineage landscape (Krishnamacharya's three students, modern Hatha, Ashtanga vinyasa, restorative, Yin, and chair yoga) that a routing agent can place a user correctly before giving instruction. Covers asana families, alignment heuristics, prop use, sequencing, and the non-negotiable injury-prevention rules. Use for any query about yoga postures, home practice design, teacher-training-level questions, or whether a given pose is safe for a given body.

Use when working with the non-metallic engineering materials — polymers, ceramics, or composites — and you need to reason about structure, processing, or properties. Covers thermoplastics versus thermosets, chain structure, glass transition, and viscoelasticity in polymers; ionic and covalent bonding, sintering, brittleness, and Weibull statistics in ceramics; and fiber-reinforced laminates, matrix and reinforcement roles, the rule of mixtures, and anisotropy in composites. Reach for it to choose a plastic, understand why a ceramic fails, or predict the stiffness of a laminate.

Applying motion study and time analysis to household work. Based directly on Lillian Gilbreth's *The Home-Maker and Her Job* and *Cheaper by the Dozen*, this skill covers the therblig-motion catalog, task decomposition, batch processing, parallelism, routine chart design, and the ergonomics of work surfaces. Use when diagnosing why a household is running out of time, designing a weekly routine, teaching task sharing to children, or reducing the friction of any repeated household task.