data-clean

data-clean is a skill for Claude Code from iowarp/clio-kit. It costs 44 tokens per session (1,521 once invoked), scanned A, original, BSD-3-Clause.

A guide for inspecting and repairing data problems such as missing values, duplicates, outliers, and invalid values before analysis. It distinguishes checking data from changing it.

In plain words
What is it for?
Use it to profile CSV or other tabular data, detect or handle missing values, check types and physically possible ranges, and apply explicitly requested repairs. It is not a plotting guide.
Why use it?
It helps avoid altering numbers without understanding the problem or applying a repair that does not match how the data is missing or what the columns mean.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the clio-analysis-skills plugin — 4 skills shipped together

Good fit Use it to profile CSV or other tabular data, detect or handle missing values, check types and physically possible ranges, and apply explicitly requested repairs. It is not a plotting guide.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/iowarp/clio-kit/data-clean
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 iowarp/clio-kit --skill data-clean
Clone the repo
git clone --depth 1 https://github.com/iowarp/clio-kit

Made for: Claude Code.

Or install clio-analysis-skills, 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 data-clean

README.md
[![agentmods](https://agentmods.dev/badge/skills/iowarp/clio-kit/data-clean/github.svg)](https://agentmods.dev/skills/iowarp/clio-kit/data-clean)
Your own site
<a href="https://agentmods.dev/skills/iowarp/clio-kit/data-clean"><img src="https://agentmods.dev/badge/skills/iowarp/clio-kit/data-clean/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 data-clean

Your own site · 80×15
<a href="https://agentmods.dev/skills/iowarp/clio-kit/data-clean"><img src="https://agentmods.dev/badge/skills/iowarp/clio-kit/data-clean.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,521 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 $0.00044 $0.01521
Opus 5.5 $0.00018 $0.00608
Sonnet 5.5 $0.00009 $0.00304
Haiku 4.5 $0.00004 $0.00152

Measured 9d ago against content hash c63617032e42, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

data-clean 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 9d 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/clio-analysis-skills/skills/data-clean/SKILL.md · 138 lines

How it starts

The opening of the file, as written. The whole thing — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Data Cleaning

Every repair here changes the numbers that come out. Look before repairing, and say what was done.

Inspect what the requested change needs

For an explicitly specified repair, inspect the affected columns, perform that repair and verify its output. Do not expand a request for interpolation into deduplication, outlier removal, memory optimisation or a general validation audit. Use the broader checks below when the user asks for cleaning or the observed data exposes a relevant problem.

clio-pandas:profile_data — shape, types, missing values, distributions, quality checks. On a raw CSV, clio-pandas:profile_csv answers the same first questions using a bounded sample; its counts/statistics need not cover the whole file.

Read three things before touching anything: how much is missing and where, whether dtypes match what the columns mean, and whether ranges are physically possible.

Missing data: how it is missing decides the fix

clio-pandas:handle_missing_data takes two separate arguments, and conflating them is the usual first failure. strategy is one of detect, impute, remove or analyze, and defaults to detect, which only reports. method is the imputation itself: mean, median, mode, forward_fill, backward_fill, interpolate. Passing strategy="median" fails with "Unknown strategy"; the call you want is strategy="impute", method="median".

The methods are not interchangeable. interpolate fills interior numeric gaps linearly by row position: [1, missing, 3, missing, 5] becomes [1, 2, 3, 4, 5]. Leading/trailing gaps, entirely missing columns and non-numeric gaps remain missing; inspect the reported imputed_count and the output. Select the intended columns. This is not time-weighted interpolation: for irregular timestamps, use a verified time-aware calculation instead. forward_fill propagates the previous observed value; backward_fill uses the next observed value. Both follow row order, so sort and separate independent series first. mode fills numeric or categorical gaps from observed values. Mean/median operate only on numeric columns. Entirely missing columns stay missing, and imputed_count counts actual fills. Preserve the input and assert expected values before accepting any transformation. If the tool chooses its own output filename, preserve the input and copy the verified result to the user's requested destination, then verify that file.

Read the full file on GitHub · 138 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 9d ago First seen · 138 lines · 44 tokens per session scan A c63617032e42

Subscribe to this mod's changes

data-clean is a skill published in the GitHub repository iowarp/clio-kit (30 stars, last pushed 8d ago), licensed BSD-3-Clause. It adds 44 tokens to every session and 1,521 once invoked, about $0.0002 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 2026-10-08.

Related

Other skills, from other repositories