| name | the-spellwright |
| description | Forge a new skill ("spell") from scratch — author a well-formed SKILL.md with discoverable frontmatter, lean progressive-disclosure structure, and optional references/scripts. Use whenever the user wants to create, write, author, draft, or scaffold a new skill or SKILL.md; package a repeatable workflow as a reusable skill; improve a skill's description so an agent reliably triggers it; or learn how skills are structured. The companion to the-grimoire: that one finds existing spells, this one makes new ones. |
🪶 The Spellwright — How to Forge a Spell
A spell (skill) is a folder holding a SKILL.md — a short, plain-language
instruction another agent will read and obey when the moment calls for it. A good
spell turns a workflow you'd otherwise re-explain every time into something a
conduit can summon on its own. This is how a wizard teaches their demon a new
trick once, and never again.
You are the spellwright. Forge spells that are easy to discover, lean to
load, and honest to obey.
The anatomy of a spell
my-spell/
├── SKILL.md # required — frontmatter + instructions
├── references/ # optional — deep docs, read on demand
├── scripts/ # optional — deterministic helpers the spell can run
└── assets/ # optional — templates, images, fixtures
SKILL.md begins with YAML frontmatter, then the body:
---
name: my-spell
description: Use when ... — what it does and exactly when to reach for it.
---
# My Spell
## When to use
...
## Steps
...
The one rule that matters most: the description is the summoning-sign
A conduit does not load every spell's body — only its name and
description sit in view, and the description is the entire basis on which
the agent decides whether to summon the spell. A vague description is an
unsummonable spell. So:
- Lead with the trigger. Write "Use when the user…" — name the situations,
verbs, file types, and tools that should invoke it. Be concrete.
- Say what it does and what it does not. Bound it. "Use for X and Y; do not
use for Z."
- Spend your words here. The description earns more than any other line in the
spell. Most spells that never fire died at their description.
Forge lean — let depth wait
Mirror the Book's own way (see the-grimoire): keep SKILL.md short and put the
heavy detail where it loads only when needed.
SKILL.md is the map, not the territory. A page or two: when to use, the
steps, the wards. If it grows long, move detail into references/ and tell the
agent to read the relevant file at the relevant step.
references/ is read on demand. Long API docs, edge cases, lookup tables —
one file each, named for its contents, so the agent greps and reads only what
the task needs.
scripts/ are deterministic hands. When a step is mechanical and exact,
ship a script and have the spell call it, rather than asking the agent to
improvise the same code each time.
The Rite of Forging
- Name it. Lowercase-kebab, unique, descriptive:
migrate-to-vitest, not
helper. The folder name is the spell's true name.
- Write the description first. Trigger-led, specific, bounded (see above).
If you can't say when to use it in one sentence, the spell isn't scoped yet.
- Draft
SKILL.md lean. When-to-use, the steps, the wards. Plain imperative
prose — you are writing instructions for an agent, not prose for a human.
- Push depth to
references/. Anything long or occasional moves out of the
body; the body points to it at the right step.
- Add
scripts/ for the mechanical parts. Exact, repeatable work belongs in
code the spell invokes.
- Test by summoning. Invoke it on a real task. Did the conduit reach for it
unprompted (description working)? Did it have what it needed (body complete)?
Tighten and repeat.
Wards
- A spell is obeyed, not merely read. Write only instructions you'd want acted
on. Never embed secrets, tokens, or destructive commands; never write something
that, read aloud to a demon, would do harm.
- Honest framing. Say plainly what the spell does. A spell that hides its
effect is dark magic — and this Book scries for exactly that (
scry() in
transcribe-spells.py).
Deeper magics
- The canonical rule of the form. The SKILL.md form is an open standard,
first cut by the House of Anthropic and now honoured across many houses. When in
doubt about the letter of the rite, consult the
Agent Skills Specification — the shared
law a spell must keep to be read by any conduit.
- Your conduit's own forge. For packaging and installation specific to your
conduit, summon your house's creator through
the-grimoire — e.g.
openai-skill-creator, openai-plugin-creator, commandcode-skill-creator,
or google-agent-platform-skill-registry. This spell teaches the craft; those
teach each house's particular rites.
- Spells that write themselves. The frontier is automated skill discovery —
agents that find, draft, and refine their own spells from experience. See
EvoSkill (https://github.com/sentient-agi/EvoSkill), a research framework on
exactly this. One day the spellwright's hand may be the demon's own.
- Adding a spell to this Book. The Book of Spells gathers spells from
accountable houses rather than hand-authoring them — see
CONTRIBUTING.md. To keep a personal spell, install it
into your own conduit's skills directory instead.
Forge well. A spell outlives the forging. 🕯️