Browse the catalog
Every entry has its own page with language patterns, when-to-use guidance, cross-references to compatible and confusable neighbors, and worked examples across twelve anchor topics.
Writing Style Library
A composable catalog of writing instructions. Pick one value from each axis - Voice, Tone, Style, Format - and the writing-instruction-builder skill assembles a prompt prefix that steers any LLM toward a precise register, reasoning pattern, and layout. Mix and match to get exactly the writing you need.
The catalog ships 97 curated entries (15 Voice, 15 Tone, 15 Style, 52 Format), each with worked examples across twelve anchor topics, side-by-side diff-pairs that isolate a single axis, recipes that bundle common combinations, and copyable format templates.
The four axes
Section titled “The four axes”Voice and Tone are distinct dimensions of one conceptual axis: Voice is who is speaking (persistent identity), Tone is how they sound right now (situational register). Style and Format are independent. Any value from any axis composes with any other.
| Axis | What it controls | Example entries |
|---|---|---|
| Voice | Persistent writer identity: worldview, characteristic concerns, professional archetype | pragmatic-architect, pastoral, journalist, coach |
| Tone | Situational register layered on top of voice | candid, warm, reverent, urgent |
| Style | Cognitive and rhetorical pattern: how ideas are sequenced | problem-solution, layered-disclosure, socratic-inquiry, dialectic |
| Format | Visual and structural container: headings, sections, layout | adr, daily-standup, slack-message, devotional-entry |
Quick start
Section titled “Quick start”The library is packaged as a Claude Code plugin, published in the Product on Purpose marketplace. Install it from inside Claude Code:
/plugin marketplace add product-on-purpose/agent-plugins/plugin install writing-style-catalog@product-on-purposeAlready installed? Run /plugin update writing-style-catalog. For the direct-from-repo and Claude.ai / Claude Desktop paths, see the installation guide.
Then compose an instruction from any combination of axes:
/writing-style-catalog:writing-instruction-builder voice=pragmatic-architect tone=candid style=problem-solution format=adrThe skill outputs a structured prompt prefix. Copy it into your system prompt or prepend it to your writing task.
Not sure which combination fits? Describe the situation instead and let entry-recommender pick it for you, composing the prompt in the same step.
How to read this site
Section titled “How to read this site”See the difference
Diff-pairs put two near-neighbor entries side by side on the same topic, varying one axis, so you can see exactly what each value changes.
Start from a recipe
Recipes are named four-axis combinations for common writing tasks, so you do not have to compose from scratch.
Grab a template
Templates give you the canonical structure for each format, ready to copy.
Learn the model
Section titled “Learn the model”- Install the plugin - marketplace and ZIP paths
- Three-Axis Model - the design behind the catalog
- Composition - how axis values combine
- Compose an Instruction - step-by-step guide
- Recommend Entries for a Situation - describe a situation, get a combination
- Add an Entry - contribute to the catalog
This project is early and experimental. The catalog, schema, and skill interface may change. See the repository README for current status.