evolve-skill

evolve-skill is a command for Claude Code from iliaal/whetstone. It costs 18 tokens per session (1,215 once invoked), scanned A, original, MIT.

A command that runs a complete improvement process for one coding-agent skill, including collecting session data, building test examples, measuring results, and trying an automated rewrite.

In plain words
What is it for?
Use it to evolve a named skill with the GEPA, MIPRO, or bootstrap optimizer and review the before-and-after scores.
Why use it?
It helps compare the skill's current behavior with an optimized version using a repeatable evaluation process instead of relying only on personal judgment.

Command for Claude Code

Written for Claude Code: argument-hint in frontmatter. Also seen: mentions subagents.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is python3 distillery/scripts/distiller.py evolve <skill> --optimizer gepa --iterations 5 --save.

Good fit Use it to evolve a named skill with the GEPA, MIPRO, or bootstrap optimizer and review the before-and-after scores.

Compare 6 commands from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/iliaal/whetstone
agentmods
npx agentmods add commands/iliaal/whetstone/evolve-skill

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for evolve-skill

README.md
[![agentmods](https://agentmods.dev/badge/commands/iliaal/whetstone/evolve-skill/github.svg)](https://agentmods.dev/commands/iliaal/whetstone/evolve-skill)
Your own site
<a href="https://agentmods.dev/commands/iliaal/whetstone/evolve-skill"><img src="https://agentmods.dev/badge/commands/iliaal/whetstone/evolve-skill/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for evolve-skill

Your own site · 80×15
<a href="https://agentmods.dev/commands/iliaal/whetstone/evolve-skill"><img src="https://agentmods.dev/badge/commands/iliaal/whetstone/evolve-skill.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 18 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,215 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00018 $0.01215
Opus 5.5 $0.00007 $0.00486
Sonnet 5.5 $0.00004 $0.00243
Haiku 4.5 $0.00002 $0.00121

Measured 1mo ago against content hash 73fe576eb25e, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

evolve-skill scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/commands/evolve-skill.md · 70 lines

How it starts

The opening of the file, as written. The whole thing — 70 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Evolve a skill

Use historical traces to diagnose weaknesses and propose a candidate. Evaluate the candidate by executing the same tasks with both full skill versions and judging the resulting outputs against one unchanged rubric.

1. Diagnose and prepare

Run harvest-sessions, then build-golden <skill> --top 20. Review candidates and label explicit successes positive, failures negative, and ungraded examples skip; run approve-golden <skill>.

Optional dspy-eval <skill> --dataset golden --emit-tasks assesses recorded outputs retrospectively. Its --skill-file changes only the judge rubric. Neither score nor score difference measures how a candidate behaves. Older before/after comparisons using this method are invalid, including those that supplied --skill-file.

Before optimization, reserve self-contained comparison cases outside the training and selection data. Each JSONL row requires:

{"case_id":"decimal-sum","task_input":"Return the sum of 17 and 25 as a JSON object with key total. No tools are needed.","acceptance_criteria":"Return exactly {\"total\":42}, with no other text."}

Replace this illustrative case with tasks relevant to the skill. Include all necessary source/context in the task or use separately reset, isolated fixtures. Historical prompts lacking their repository state are not executable fixtures. Freeze an independent rubric in a text file before seeing either output. Define correctness, applicable procedure, and conciseness on a 0–10 scale.

2. Propose a candidate

python3 distillery/scripts/distiller.py evolve <skill> --optimizer gepa --iterations 5 --save

This step uses paid model calls; follow the user's spending authorization. Keyword fitness is a lexical proxy restricted to positive references or curated expected_output, never failed traces. LLM-judge fitness generates single-turn responses, not tool-using execution. Neither proves agentic improvement. Inspect the diff and size constraints; unchanged output is a null result, not proof of Pareto optimality.

Read the full file on GitHub · 70 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 1mo ago Changed · -92 lines · -14 tokens per session 73fe576eb25e
  2. 1mo ago First seen · 162 lines · 32 tokens per session scan A 70f26c526290

Subscribe to this mod's changes

evolve-skill is a command published in the GitHub repository iliaal/whetstone (35 stars, last pushed 2d ago), licensed MIT. It adds 18 tokens to every session and 1,215 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.