evolve-skill-library

evolve-skill-library is a skill for Claude Code, Codex from bikeread/promethos. It costs 29 tokens per session (701 once invoked), scanned A, original, MIT.

A guide for maintaining a collection of reusable agent instructions, called skills. It helps organize, combine, retire, or reshape skills as the collection changes.

In plain words
What is it for?
Use it to map what each skill is for, find duplicate or missing coverage, and decide which material should be merged, retired, or kept.
Why use it?
It reduces confusion caused by overlapping, outdated, unused, or poorly scoped skills.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to map what each skill is for, find duplicate or missing coverage, and decide which material should be merged, retired, or kept.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/bikeread/promethos/evolve-skill-library
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add bikeread/promethos --skill evolve-skill-library
Clone the repo
git clone --depth 1 https://github.com/bikeread/promethos

Made for: Claude Code, Codex.

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-library

README.md
[![agentmods](https://agentmods.dev/badge/skills/bikeread/promethos/evolve-skill-library/github.svg)](https://agentmods.dev/skills/bikeread/promethos/evolve-skill-library)
Your own site
<a href="https://agentmods.dev/skills/bikeread/promethos/evolve-skill-library"><img src="https://agentmods.dev/badge/skills/bikeread/promethos/evolve-skill-library/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-library

Your own site · 80×15
<a href="https://agentmods.dev/skills/bikeread/promethos/evolve-skill-library"><img src="https://agentmods.dev/badge/skills/bikeread/promethos/evolve-skill-library.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 29 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 701 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 $0.00029 $0.00701
Opus 5.5 $0.00012 $0.00280
Sonnet 5.5 $0.00006 $0.00140
Haiku 4.5 $0.00003 $0.00070

Measured 2mo ago against content hash d49754fb4525, 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-library 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 2mo 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.

skills/evolve-skill-library/SKILL.md · 79 lines

How it starts

The opening of the file, as written. The whole thing — 79 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Goal

Keep the skill library coherent by merging overlaps, retiring stale material, and promoting only the patterns that earn long-term reuse.

Inputs

  • Current skill inventory
  • Usage history or anecdotal friction
  • Repeated failures, corrections, or missing patterns

Non-Goals

  • Rewriting the entire library from scratch without evidence
  • Expanding scope just to make the library feel more complete

Workflow

Trigger signals

  • Two skills seem to overlap in scope
  • A skill has not been triggered in a long time
  • Users complain the library is confusing or hard to navigate
  • Skill count is growing without clear value

1. Inventory the library by behavior, not by file count

List each skill's purpose, trigger, current usefulness, and nearest neighbors. Note which skills have strong evidence of repeated use and which only look important in theory. Success criteria: The library is mapped as a set of decision points, not a flat list of filenames.

2. Detect overlap, gaps, and drift

Compare neighboring skills to find duplicate triggers, missing coverage, stale assumptions, and places where a skill has started to sprawl beyond its original decision area. Success criteria: Each suspicious area is labeled as overlap, gap, or drift, so the next action is obvious.

3. Check for buried or drifting guardrails

Review whether risky behavior, approval logic, or escalation rules have drifted out of the guard layer and into general-purpose skills. Success criteria: Cross-cutting guardrail logic is either kept visible in the guard layer or intentionally referenced there.

4. Decide keep, merge, split, archive, or promote

Apply one explicit rule set to each candidate change: preserve a skill that is still distinct and useful, merge only when two skills answer the same decision, split only when one skill contains multiple decision points, archive when the pattern is no longer in use, and promote when a repeated rule has earned a skill. Success criteria: Every decision has a rationale tied to usage evidence or library clarity.

Read the full file on GitHub · 79 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. 2mo ago First seen · 79 lines · 29 tokens per session scan A d49754fb4525

Subscribe to this mod's changes

evolve-skill-library is a skill published in the GitHub repository bikeread/promethos (33 stars, last pushed 7mo ago), licensed MIT. It adds 29 tokens to every session and 701 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.

Related

evolve-skill-library compared with skills from other repositories

evolve-skill-library next to 6 skills from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
evolve-skill-librarybikeread/promethosSkill337mo agoMITA29Claude Code, Codex
imagegenopenai/codexSkill133kyesterdayApache-2.0A113Codex
playwright-climicrosoft/playwrightSkill99kyesterdayApache-2.0A19Claude Code
local-ai-agentsmicrosoft/ai-agents-for-beginnersSkill79k4d agoMITA200Claude Code, Codex
systematic-debuggingobra/superpowersSkill313k3d agoMITA21Claude Code
next-cache-components-adoptionvercel/next.jsSkill143ktodayMITA95Claude Code
next-partial-prefetching-adoptionvercel/next.jsSkill143ktodayMITA103Claude Code