tune

tune is a skill for Claude Code, Codex from duthaho/skillhub. It costs 157 tokens per session (2,037 once invoked), scanned A, original, MIT.

A skill that reviews recent coding-agent sessions and project settings to find mistakes that keep happening. It proposes small changes to the project’s instructions, permissions, or scripts to prevent those mistakes.

In plain words
What is it for?
Use it to audit recent transcripts, bugfix notes, rules, permissions, and hooks; rank repeated issues; and suggest one-line harness improvements.
Why use it?
It addresses recurring problems in the agent’s working setup instead of treating every correction as a one-off fix.

Skill for Claude CodeCodex

Part of the daily plugin — 4 skills shipped together

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.

agentmods
npx agentmods add skills/duthaho/skillhub/tune
Any agent
npx skills add duthaho/skillhub --skill tune
Clone the repo
git clone --depth 1 https://github.com/duthaho/skillhub

Made for: Claude Code, Codex.

Or install daily, the plugin that ships this one along with the rest of its 4 skills.

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 tune

README.md
[![agentmods](https://agentmods.dev/badge/skills/duthaho/skillhub/tune.svg)](https://agentmods.dev/skills/duthaho/skillhub/tune)
Your own site
<a href="https://agentmods.dev/skills/duthaho/skillhub/tune"><img src="https://agentmods.dev/badge/skills/duthaho/skillhub/tune.svg" alt="Measured on agentmods" height="20"></a>
Per session 157 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,037 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00157 $0.02037
Opus 5 $0.00078 $0.01019
Sonnet 5 $0.00031 $0.00407
Haiku 4.5 $0.00016 $0.00204

Measured 5d ago against content hash 234f81fff9a8, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

tune 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 5d 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/skills/tune/SKILL.md · 168 lines

How it starts

The opening of the file, as written. The whole thing — 168 lines — stays where its author put it; the contents beside it link to each section on GitHub.

tune — the harness retro

/tune — audit the current project's harness against recent sessions /tune all — widen across every project under ~/.claude/projects/

Answer one question: what keeps going wrong across sessions, and what one-line change would make it impossible next time? Correcting the agent fixes one session; correcting the harness fixes every session after it. The evidence is already on disk — the transcripts recorded every correction, every retyped instruction, every permission prompt. This skill reads them so the user doesn't repeat them.

Step 0 — Scope, then inventory

Scope: default is the current project's transcripts — the last ~10 sessions or 2 weeks, whichever is smaller — from ~/.claude/projects/<project-dir>/*.jsonl (the dir name is the project path with /-). /tune all widens to every project; mining gets shallower per project, say so.

Inventory the harness first — findings only mean something against the baseline. Read: user + project CLAUDE.md, the installed skills (names + descriptions), settings.json / settings.local.json (permissions, hooks). Also read out/tune/learnings.md (past accepted/rejected — don't re-propose what was rejected), out/tune/principles.md if present (promoted cross-cutting principles — a lens for judging new findings), and out/dev/bugfix-log.md if present (recurring root causes are harness findings too).

Step 1 — Mine the transcripts (cheap models, parallel)

Bulk transcript reading is a job for a cheap model, not the frontier one — spawn the miners with model: haiku, one per evidence stream, concurrently:

  • Corrections: user messages that correct, redo, or undo the agent's work — especially the same correction phrased across different sessions. The strongest signal there is.
  • Friction: permission prompts approved again and again, commands the user retypes, tool errors hit repeatedly (a broken alias, a missing binary, a path that's always wrong the first time).
  • Ignored rules: places where a CLAUDE.md rule already exists and the transcript shows it being violated anyway — prose that failed needs a mechanism, not more prose.
  • Re-derived procedures: multi-step sequences the agent works out from scratch in session after session — candidates for a script or a skill.
  • Dead weight: rules and skills that never once became relevant in the mined window.

Read the full file on GitHub · 168 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. 5d ago First seen · 168 lines · 157 tokens per session scan A 234f81fff9a8

Subscribe to this mod's changes

tune is a skill published in the GitHub repository duthaho/skillhub (9 stars, last pushed 11d ago), licensed MIT. It adds 157 tokens to every session and 2,037 once invoked, about $0.0008 per session on Opus 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 2026-08-31.

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