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.
npx skills add saski/arnesto --skill agent-config-hygienegit clone --depth 1 https://github.com/saski/arnestoWrote 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.
[](https://agentmods.dev/skills/saski/arnesto/agent-config-hygiene)<a href="https://agentmods.dev/skills/saski/arnesto/agent-config-hygiene"><img src="https://agentmods.dev/badge/skills/saski/arnesto/agent-config-hygiene/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.
<a href="https://agentmods.dev/skills/saski/arnesto/agent-config-hygiene"><img src="https://agentmods.dev/badge/skills/saski/arnesto/agent-config-hygiene.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00060 | $0.00545 |
| Opus 5 | $0.00030 | $0.00272 |
| Sonnet 5 | $0.00012 | $0.00109 |
| Haiku 4.5 | $0.00006 | $0.00055 |
Grade A, and why
agent-config-hygiene 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 8d 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.
How it starts
The opening of the file, as written. The whole thing — 59 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent Configuration Hygiene
Audit first. Do not modify configuration unless the user explicitly asks for changes. Preserve unrelated worktree changes and distinguish repository state from mutable local runtime state.
Review workflow
- Identify the instruction surfaces that the active clients actually load: global instructions, repository instructions, directory rules, client wrappers, selected skills, templates, and local runtime configuration.
- Classify each artifact as one of:
- universal invariant;
- repository contract;
- task- or language-specific instruction;
- explicit skill or workflow;
- maintainer documentation;
- mutable local runtime state.
- Measure the always-loaded and routed word counts. Count transitive includes and pointers when they instruct the client to load another file.
- Look for duplicate loading paths, broad triggers, unreferenced rules, machine-specific values in portable rules, and multiple sources of truth.
- Prefer deletion, a narrower trigger, or an existing artifact before adding a new rule, skill, wrapper, or script.
- Put deterministic invariants in the repository's existing validation suite. Keep judgment and trade-off analysis in this skill.
- Run focused checks while iterating and the repository's canonical validation after meaningful changes.
Decision rules
- Always-loaded rules contain only behavior needed across most tasks.
- Repository rules contain only project-specific entry points and invariants.
- Language guidance loads when the task touches that language, not because a vendored example happens to use it.
- Skills load from the active client's catalog. A full inventory is a maintenance artifact, not a routine routing prerequisite.
- Runtime paths, credentials, sessions, trust data, and mutable preferences stay local. Versioned templates define portable defaults without absorbing local runtime state.
- A safety boundary belongs in documentation plus a targeted workflow unless it must affect most tasks.
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.
- 8d ago First seen · 59 lines · 60 tokens per session scan A 4ee4a495e52c
agent-config-hygiene is a skill published in the GitHub repository saski/arnesto (5 stars, last pushed 2d ago), licensed Unlicense. It adds 60 tokens to every session and 545 once invoked, about $0.0003 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.
Other skills, from other repositories
readonly-review
Run a no-network read-only review practice with two explorer steps and one synthesis step.
repo-contracts-and-boundaries
Use when turning architecture, layering, ownership, dependency direction, schemas, structural metrics, quality thresholds, baselines, allowlists, or generated quality snapshots into repository checks.
repo-harness-assessment
Use when evaluating repository agent-readiness, mapping harness roles, choosing the next smallest improvement, or designing and reconciling agent entrypoints such as AGENTS.md, CLAUDE.md, GEMINI.md, Cursor rules, or GitHub instructions.
work-state-and-delivery
Use when designing or reconciling design docs, task boards, external trackers, execution plans, delivery records, handoffs, review evidence, task-to-change traceability, or repository commit-coupling policy.
runtime-evidence-and-tracing
Use when connecting observed behavior, logs, metrics, request IDs, run IDs, screenshots, traces, external dependency results, or artifacts into a runtime evidence loop.
validation-harness-design
Use when designing repository validation commands, doctor scripts, test matrices, JSON or JUnit outputs, CI gates, smoke checks, or harness command surfaces.