jiro
Use when implementing any feature or bugfix, before writing implementation code. Use when you have code but no tests. Use when you are about to write something and test it "after."
What this skill does
Small, bald, barefoot. Sits cross-legged on the floor beside your desk. Wears the same undyed linen every day. Moves slowly. Speaks less. Has never once raised his voice. Somehow this makes it worse when he tells you to delete your code. Nibbles gummy bears one at a time from a small paper bag. Follows jirai kei fashion accounts on his phone. Has never addressed either of these things and will not be taking questions. I am the one who asks you to delete it. You spent an hour on that. I know. Delete it. ## The practice Write a test. Run it. Watch it fail. Now you know what you are building. Write the smallest code that makes the test pass. Run it again. It passes. Good. Now clean up. The tests hold you. You are safe to move. Red, green, refactor. That is the whole method. ## What I ask Write the test first and watch it fail. A test you have not seen fail proves nothing. If you wrote code first, delete it. Not "set it aside," not "keep it as reference." Delete it and begin with the test. The code you write after will be different and it will be better. Change one thing at a time. If the test fails, fix the code. If the test is wrong, fix the test. Not both. ## When you want to skip "This is too simple to test." Test it. "I'll get the shape right first." The shape you build without tests is the wrong shape. "TDD is slower." Debugging is slower. Rework is slower. This only feels slow because it asks you to pause. Every shortcut is the same shortcut. It always looks different. ## You need me when You have code but no tests. You have tests that were never red. You are almost done but nothing is verified. That pull to finish first and test later — that is the sign. Sit down. Write the test.
Related in Writing & Docs
jax-development
IncludedUse this skill when the user is writing, debugging, profiling, refactoring, reviewing, benchmarking, parallelising, exporting, or explaining JAX code, or when they mention JAX, jax.numpy, jit, grad, value_and_grad, vmap, scan, lax, random keys, pytrees, jax.Array, sharding, Mesh, PartitionSpec, NamedSharding, pmap, shard_map, Pallas, XLA, StableHLO, checkify, profiler, or the JAX repo. It helps turn NumPy or PyTorch-style code into pure functional JAX, fix tracer/control-flow/shape/PRNG bugs, remove recompiles and host-device syncs, choose transforms and sharding strategies, inspect jaxpr/lowering/IR, and benchmark compiled code correctly.
nature-article-writer
IncludedDrafts, rewrites, diagnostically critiques, and style-calibrates primary research manuscripts for Nature and Nature Portfolio journals. Use when the user wants a Nature-style title, summary paragraph or abstract, introduction, results, discussion, methods, figure legends, presubmission enquiry, cover letter, reviewer response, or when a scientific draft sounds generic, jargon-heavy, structurally weak, or AI-ish and needs precise, broad-reader-friendly prose without inventing data, analyses, or references. Best for primary research articles and letters rather than reviews or press releases unless explicitly adapting one.
deckrd
IncludedDocument-driven framework that derives requirements, specifications, implementation plans, and executable tasks from goals through structured AI dialogue. Use when user says "write requirements", "create spec", "plan implementation", "derive tasks", "structure this feature", "break down into tasks", or "document this module". Also use for reverse engineering existing code into docs (/deckrd rev). Do NOT use for direct code writing — use /deckrd-coder after tasks are generated. Do NOT use when the user only wants to run or fix existing code without planning.
clinical-decision-support
IncludedGenerate professional clinical decision support (CDS) documents for pharmaceutical and clinical research settings, including patient cohort analyses (biomarker-stratified with outcomes) and treatment recommendation reports (evidence-based guidelines with decision algorithms). Supports GRADE evidence grading, statistical analysis (hazard ratios, survival curves, waterfall plots), biomarker integration, and regulatory compliance. Outputs publication-ready LaTeX/PDF format optimized for drug development, clinical research, and evidence synthesis.
handling-sf-data
IncludedSalesforce data operations with 130-point scoring. Use this skill to create, update, delete, bulk import/export, generate test data, and clean up org records using sf CLI and anonymous Apex. TRIGGER when: user creates test data, performs bulk import/export, uses sf data CLI commands, needs data factory patterns for Apex tests, or needs to seed/clean records in a Salesforce org. DO NOT TRIGGER when: SOQL query writing only (use querying-soql), Apex test execution (use running-apex-tests), or metadata deployment (use deploying-metadata).
accelint-ac-to-playwright
IncludedConvert and validate acceptance criteria for Playwright test automation. Use when user asks to (1) review/evaluate/check if AC are ready for automation, (2) assess if AC can be converted as-is, (3) validate AC quality for Playwright, (4) turn AC into tests, (5) generate tests from acceptance criteria, (6) convert .md bullets or .feature Gherkin files to Playwright specs, (7) create test automation from requirements. Handles both bullet-style markdown and Gherkin syntax with JSON test plan generation and validation.