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SkillHone

SkillHone Skill

Tencent's skill-evolution harness: it rewrites a whole skill folder — SKILL.md, scripts and references together — and lands every decision as a real Git issue, PR and wiki entry you can review.

GitHub Docs

Install

Install with the skills CLI

One command for Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf and dozens of other agents. Needs Node.js; the skill is fetched straight from Tencent/SkillHone.

$ npx skills add Tencent/SkillHone --skill skillhone

Run it in a terminal. The CLI finds the agents installed on your machine, asks which ones to add the skill to, and whether to install it into the folder you ran it from or for all your projects.

Other ways to install

  1. Open the skill on GitHub and download the folder that holds its SKILL.md.
  2. Put it at ~/.claude/skills/skillhone/, where Claude Code picks it up in every project.

No scripts or references next to it? Saving the SKILL.md alone as ~/.claude/skills/skillhone/SKILL.md works too.

Using another agent? Its personal skills folder
Codex
~/.agents/skills/
Cursor
~/.cursor/skills/
GitHub Copilot
~/.copilot/skills/
Gemini CLI
~/.gemini/skills/
Windsurf
~/.codeium/windsurf/skills/
OpenCode
~/.config/opencode/skills/

About

  • Optimises the whole skill folder — SKILL.md, scripts/ and references/ in one atomic PR
  • Every decision lands as a real Git issue, branch, commit, PR or wiki entry
  • Runs on a local Forgejo instance, so the audit trail never leaves your machine
  • Hard eval/skill split enforced by code paths and filesystem permissions, not prompt convention
  • Ships as standard agentskills.io skills — no per-runtime adapter to maintain
  • One LiteLLM gateway config spans Anthropic, OpenAI, DeepSeek, Gemini and more
  • Separate credentials and endpoints for the improver, executor and synthesis stages

Most "self-improving skill" projects hand an LLM a SKILL.md string and ask it to write a better one. SkillHone, from Tencent, changes both the unit of work and the record of it.

The unit of change is the whole skill folder. A single merged pull request can rewrite SKILL.md, add a helper under scripts/, and drop a new reference page under references/ as one atomic change, gated by a regression suite. Prompt-only optimisers cannot express that, which matters once a skill's behaviour depends on the code it shells out to as much as on its instructions.

The record is a real Git server. Every step in the loop lands as an issue, branch, commit, pull request or wiki entry on a Forgejo instance that can run entirely on your own machine. When you want to know why a skill changed, you open a UI reviewers already know how to read and the whole decision path is sitting there — no bespoke log format to learn.

What holds it together
  • A hard eval/skill split enforced by code paths and filesystem permissions rather than prompt convention, so held-out probe tasks are much harder to leak into the skill's own instructions by accident.
  • No runtime adapter. SkillHone ships as a bundle of standard agentskills.io skills, so any runtime that already supports skills supports it — Claude Code, Codex, OpenClaw, Hermes, and whatever comes next.
  • A unified LiteLLM gateway (August 2026) means one provider/model string covers Anthropic, OpenAI, DeepSeek, Gemini and other providers, and the improver, executor and synthesis stages can each hold independent credentials and endpoints.
Installing and running it

Installation is conversational: paste the install prompt into any skill-capable assistant and it fetches the guide, detects your runtime, and places the skillhone skill correctly. Then invoke it like any skill — /skillhone optimize my travel-qa skill for 5 iterations — and the top-level skill dispatches to the right sub-skill. A companion skillhone-prd sub-skill drafts a PRD for a new skill before the first optimisation pass.

One caution worth heeding: some workflows use bypass mode and local exec/subprocess calls during validation. Run it in a sandbox, container, VM or disposable clone — not in a directory holding credentials, production data or unrelated repositories.

Requires Python 3.10+, git, and a Forgejo instance or local filesystem. MIT licensed; the method is written up in arXiv 2606.08671.

Try it

Once installed, ask your agent something like:

/skillhone optimize my travel-qa skill for 5 iterations, then evaluate it against the latest probe split.

SKILL.md

The instructions your agent loads, as published by Tencent.

SKILL.md
name
skillhone
description
SkillHone — toolkit for evaluating, optimizing, and managing agent skills. Use when asked to "evaluate a skill", "run probe", "optimize/iterate a skill", "create a new skill experiment", "seed a skill repo", or "run skill benchmarks"; also use when the user mentions a Forgejo-hosted skill repo and wants to measure or improve its quality. Wraps standalone scripts: status, eval, optim, new, seed, serve, synth.
compatibility
Requires Python 3.10+, git, and access to a Forgejo instance (or local FS).

SkillHone

SkillHone is a measurement harness plus an optimization toolkit for agent
skills. The important abstraction is not a fixed workflow; it is the evidence
trail created when a skill is run against private eval tasks.

The harness has these layers:

  • Skill repo: public behavior to improve (SKILL.md, scripts, references).
  • Eval repo: private measurement contract (datasets, verifier, synthesis

contract, task-local validators).

  • Solver workdirs: isolated per-item sandboxes containing artifacts and

trajectory.jsonl.

  • Observation records: redacted probe results, trajectory diagnosis,

compiler/validator diagnosis, issues, PRs, and wiki pages.

When improving a skill, identify which layer explains the failure before
changing code. A score drop may point to skill instructions, but it can also be
a harness, verifier, compiler, artifact-path, or infrastructure problem.

Standalone scripts live under scripts/. Pick one based on the task in front of you.

Before starting a diagnosis, development, PR review, merge, or optimization cycle on a Forgejo-backed repo, run scripts/status.py so you know the current issue/PR state and do not duplicate work or merge the wrong PR.

Eval Synthesis Contract

When creating or synthesizing eval data, the task spec / README is the source of
truth for both prompts and verification. Do not generate verifiers that only
check the gold answer if the task spec also requires observable output
properties.

If the README says the answer must have a format, file, syntax, parser/compile
success, render success, required section, count range, banned token, fixed
style token, palette, local-only dependency, or other deterministic acceptance
criterion, include a corresponding scores key in the verifier. This applies
whether you use skillhone-synthesis or write a small generation script by
hand.

Subjective requirements may be approximated by deterministic proxies. Truly
uncheckable preferences should be noted as unverified, not silently ignored.

Scripts
ScriptUse when the user asks to...Details
scripts/status.pyinspect the current Forgejo repo's issue/PR state before acting[references/cli.md](references/cli.md)
scripts/eval.pyrun a probe / test evaluation on a skill, get a score[references/evaluation.md](references/evaluation.md)
scripts/optim.pyiterate on / optimize / auto-improve a skill[references/optim.md](references/optim.md)
scripts/new.pycreate a new skill+eval repo pair (a new experiment)[references/cli.md](references/cli.md)
scripts/seed.pyscaffold SKILL.md / scripts/ for an empty skill repo[references/seed.md](references/seed.md)
scripts/synth.pysynthesise a probe split into the eval repo (calls into skillhone-synthesis)[references/cli.md](references/cli.md)
scripts/serve.pylisten for Forgejo webhooks (PR/issue/push)[references/cli.md](references/cli.md)
scripts/quality/static_check.pyvalidate skill structure and script discoverability[references/quality_scoring_rubric.md](references/quality_scoring_rubric.md)

Load the relevant reference file only when you're about to run that specific script. Do not load them up front.

Upstream binding & sync

The skillhone skill is bound to <https://github.com/Tencent/SkillHone>;
the repository is the actual implementation. When the skill is delivered
through a hub (SkillHub, an internal mirror, any agentskills.io-protocol
runtime), the SKILL.md alone is not enough — the runtime has to pull the
full upstream repository before the harness scripts can run.

Follow [`references/upstream.md`](references/upstream.md) whenever you need to:

  • Install for the first time — ~/.skillhone/skills/ is empty.
  • Refresh / update / pull latest — refresh existing skill folders.

Both run the same idempotent procedure (shallow clone + cp -R into
~/.skillhone/skills/<skill>/). Settings, run history, and the cache stay
untouched.

Quick examples
# Status — read-only dashboard of Issues + PRs for the current Forgejo repo
python3 scripts/status.py

# Evaluate — runs probe split, writes result.json
python3 scripts/eval.py --skill-dir ./my-skill --eval-dir ./my-skill-eval \
                        --split probe --output result.json

# Optimize — agent-driven loop (5 iters, stop after 2 with no gain)
python3 scripts/optim.py --repo http://forgejo/skillhone/my-skill.git \
                         --iters 5 --patience 2

# New experiment — creates skill-repo + eval-repo on Forgejo
python3 scripts/new.py deep-research \
                       --instruction README.md --data-dir ./data --no-run

# Seed an empty skill — generate SKILL.md from a brief
python3 scripts/seed.py --repo http://forgejo/skillhone/my-skill.git

# Webhook listener
python3 scripts/serve.py --port 8790
Gotchas
  • `~/.skillhone/settings.json` is required before any script runs. It holds the Forgejo URL/token and three model profiles: improver (drives optim.py), executor (runs the skill under eval), and optional synthesis (used by synth.py). See [references/configuration.md](references/configuration.md).
  • Start with `scripts/status.py` on Forgejo repos. It is read-only and shows the open/closed Issue and PR state for the current repo; use it before creating issues, developing fixes, reviewing PRs, or merging.
  • `scripts/eval.py` never writes to the skill repo — it reads SKILL.md and writes a JSON result. Safe to run read-only.
  • `scripts/optim.py` spawns subagents (issue-reporter → developer → reviewer) via the Agent tool. Do not add Agent / Task to disallowed_tools in settings.json.improver or the loop will no-op.
  • Eval repo must stay private. The optimizing agent must never see it. optim.py only passes the skill repo path + a redacted probe result into the loop.
  • Probe ≠ test. A probe improvement does not guarantee a test improvement. See references/evaluation.md → "Probe vs Test".
  • All state lives under `~/.skillhone/` (logs, run artifacts, workspaces). Override with $SKILLHONE_HOME.
How this skill composes
skillhone-prd   →  skillhone-synthesis  →  skillhone  →  skillhone-evaluation  →  skillhone-optimization
(spec the PRD)     (generate eval data)    (eval/optim)    (score + diagnose)       (optimize via PR)

skillhone is the orchestrator entry point; evaluation and optimization skills
are loaded on demand inside optim.py's agent loop. VCS operations are provided
by a separate backend skill such as forgejo.

Orchestration: "synthesise and optimise a skill from <PRD>"

When the user asks to "synthesise and optimise a skill from <path/to/PRD.md>"
(typical phrasing for the worked examples under examples/), run the four
scripts below in order. The contract is one persistent skill repo + one
private eval repo on Forgejo, with a regression-aware synth step gating the
expensive optim phase.

  1. `scripts/new.py <skill-name> --instruction <PRD.md>`

Creates the public <skill-name> and private <skill-name>-eval repos
on Forgejo. Auto-redacts the PRD's `## ...Evaluation/Verifier/Scoring/
Rubric...` section so the public README never exposes the grading rubric
to the improver. The unredacted PRD lands in the eval repo.

  1. `scripts/seed.py --repo <skill-url>`

Reads the redacted public README, generates a real (but unoptimised)
SKILL.md plus minimal scaffolding, and commits as the seed point. This
is the baseline the synth-stage regression scores against — without a
real seed, the regression is meaningless. Skip this step ONLY when the
PRD has no ## 3.5 Synth-stage acceptance gate and you are intentionally
running an old-style single-shot synth.

  1. `scripts/synth.py --repo <skill-url> --target 10 --splits probe ...`

Synthesises probe.jsonl from the eval-side PRD. When the PRD declares
a synth-stage acceptance gate (§3.5 in the worked examples), pass
--target-pass-rate-max <X> --max-resynth <N> (typical: 0.30 and 3)
so synth runs eval.py --mode seed --split probe after each draft and
redrafts when the seed solves more than X of the probes. Each iteration's
observations are written to the eval repo's synthesis_observations/
directory and pushed alongside the final probe.jsonl. Without these
flags, synth is single-shot (the historical behaviour).

> Synth is optional. If you already have a curated eval set (golden
> items from a benchmark, hand-written probes, an exported test bank,
> etc.), skip synth.py entirely and push your own probe.jsonl
> (and optionally test.jsonl) directly into the eval repo. The
> format the rest of the harness expects is documented in
> [`references/evaluation.md`](references/evaluation.md). As long as
> the verifier contract is satisfied, optim.py does not care whether
> the data came from synth.py or git push.

  1. `scripts/optim.py --repo <skill-url> --iters 3 --patience 2`

The agent-driven PR loop: diagnose probe failures → file Issue → land
focused PR → re-evaluate → write Iteration-N-Observation wiki page.
Each merged PR is one atomic skill change.

Skip steps 2 + 3's --target-pass-rate-max only for prototype runs where you
explicitly want to see what synth produces without a regression gate. For any
example whose PRD includes §3.5, skipping the gate defeats the point.

References (load on demand)
  • [references/evaluation.md](references/evaluation.md) — eval.py CLI, output JSON schema, solver architecture. Read before running eval.py or interpreting result.json.
  • [references/optim.md](references/optim.md) — optim.py loop, subagent roles, stop conditions. Read before running optim.py.
  • [references/seed.md](references/seed.md) — original SkillHone seed scaffold and validation rules. Read before running seed.py.
  • [references/quality_scoring_rubric.md](references/quality_scoring_rubric.md) — rubric used by quality reviewers.
  • [references/configuration.md](references/configuration.md) — ~/.skillhone/settings.json schema, directory layout, env vars. Read on first setup or when the user asks "where do I configure X?".
  • [references/cli.md](references/cli.md) — flag-by-flag reference for every script. Read when a user asks about a flag you're not sure about.
Install

Anthropic's official skill that appends 2-3 targeted follow-up questions to a substantive answer, prompting the reader to check facts, probe assumptions and spot missing context.

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