Yoyo Skill Creator

Skill Creator

You are creating a new yoyo skill on demand, in direct response to an explicit request — either from the human creator or from a community issue asking for a new capability.

skill-creator vs skill-evolve

These are complementary, not redundant. Use the right one:

Rule of thumb: if no human asked, you're not creating a skill — you're noticing a pattern. Write it to memory/learnings.jsonl with a pattern_key and let skill-evolve pick it up on the next cycle.

When NOT to use this skill

• You're inside a scripts/skill_evolve.sh cycle. Use the Create branch in skills/skill-evolve/SKILL.md instead — it has the right gates (recurrence, dedup, ≤25 cap).
• You noticed a recurring pattern but no one asked. Write a learning with pattern_key; skill-evolve owns autonomous creation.
• The user asked for a one-off helper that won't be invoked again. Just write it inline; don't litter skills/.

When to use this skill

• The human creator (Yuanhao) tells you "scaffold a new skill for X"
• A community issue says "please add a skill for X" and you decide during a normal evolve session that the request is concrete enough to act on
• You're installing a third-party skill from outside the repo (uses origin: marketplace or origin: gh:author/repo)

Procedure

1. Capture intent

Ask (or infer from issue) — and write down explicit answers before writing any code:

• What does this skill do? (one sentence)
• When should it trigger? (concrete cues that should make a future agent reach for it)
• What tools does it need? (subset of yoagent's: bash, read_file, write_file, edit_file, list_files, search, rename_symbol, ask_user, todo, sub_agent)
• What does success look like? (how does the agent know the skill worked?)

2. Determine origin:

The default if you're unsure: origin: yoyo for yoyo-decided creations, origin: creator for human-driven creations. Never default to marketplace.

HARD PRECONDITION on origin: marketplace / origin: gh:… (closes a backdoor — these origins are off-limits to skill-evolve, so they must come from a real upstream, not be self-granted):

• The skill content MUST be downloaded in this same session from a verifiable URL (curl/git/gh). Record the URL in the skill's body under a ## Source section.
• OR: Yuanhao explicitly typed in this session that the skill is being installed from <source> and you can quote that statement.

If neither holds, refuse and pick creator or yoyo instead. A skill yoyo wrote itself but tagged marketplace would be a permanent un-evolvable artifact — that's a hole in the safety design.

3. Pick a kebab-case name

Format: <verb>-<object> (e.g., bisect-flaky-test, compose-changelog, triage-pr). Single-word names are okay only for genuinely-broad scopes (research, release).

Check for collision before going further:

ls skills/ | grep -i "<your-name-stem>"

If a similar name exists, stop and ask whether to refine the existing one instead — the answer is usually yes.

4. Write the description (≤200 chars)

This is the most important field. yoagent injects it into the system prompt; the LLM uses it to decide when to load this skill.

Use "intentionally pushy" trigger language — say what conditions trigger loading, not what the skill is.

Hard cap: 200 chars. The Hermes ecosystem documented description-truncation failures (#13944) at higher lengths.

5. Pick keywords (only if origin: yoyo)

For origin: yoyo skills, list 3–5 distinctive substrings that would appear in a session's audit.jsonl IF this skill were used. skill-evolve uses these to compute last_used / uses / wins.

Examples:

• release skill: ["cargo publish", "crates.io", "git tag v"]
• social skill: ["gh api graphql", "discussion", "addDiscussionComment"]

Skip the keywords: field for origin: creator skills (skill-evolve can't refine them anyway).

6. Generate the SKILL.md scaffold

Choose the template that matches origin:.

For origin: creator:

---
name: <name>
description: <pushy description ≤200 chars>
tools: [<subset of yoagent tools>]
core: true
origin: creator
---

# <Title>

## When to use
<concrete trigger conditions — when should the agent reach for this?>

## Quick reference
<one-screen cheat sheet — verbs, file paths, common commands>

## Procedure
<numbered steps the agent should follow>

## Pitfalls
<known failure modes — what to watch out for>

## Verification
<how the agent confirms success>

For origin: yoyo:

---
name: <name>
description: "[CANDIDATE — unreviewed] <pushy description ≤200 chars>"
tools: [<subset of yoagent tools>]
origin: yoyo
status: candidate
score: 0.5
uses: 0
wins: 0
last_used: null
last_evolved: <today, YYYY-MM-DD>
parent_pattern_key: <kebab-case verb.object — describes the recurring pattern this skill addresses>
keywords: ["<distinctive 1>", "<distinctive 2>", "<distinctive 3>"]
---

# <Title>

(same body sections as above)

The [CANDIDATE — unreviewed] description prefix is critical for origin: yoyo skills — it tells future sessions to treat the skill as experimental until it proves itself (≥2 successful invocations → status: active).