Data Quality Auditor
Audit datasets for completeness, consistency, accuracy, and validity.
Before & after
Same prompt, same agent — the only difference is the skill.
Auditing data quality before training is a smart move. Here's what to check: - **Completeness** — how many missing values, and in which columns - **Consistency** — conflicting or contradictory values - **Accuracy** — values that are wrong or out of expected ranges - **Validity** — values that don't match the expected format or type - **Duplicates** — repeated records that could skew training - **Outliers** — extreme values that may be errors or genuine edge cases I'd start by profiling the dataset — get distributions, null counts, and unique value counts per column. Then investigate anything that looks off. Can you share the dataset or describe its structure?
DATA QUALITY AUDIT — profile first, judge second. Numbers below are the
shape of a real audit; run against your file for actuals.
COMPLETENESS
column null % verdict
email 0.2% fine
signup_date 0% fine
last_purchase 34% ⚠ — is null "never purchased" or missing data?
This distinction changes your model. Confirm
before imputing.
region 11% investigate — clustered in one signup source?
CONSISTENCY
• 47 rows: last_purchase BEFORE signup_date. Impossible. Data error,
not an outlier — exclude or fix, don't feature-engineer around it.
• account_status has "active", "Active", "ACTIVE" — 3 spellings, one
state. Silent cardinality inflation; models will treat them as
distinct.
VALIDITY
• 12 emails don't parse. • 3 signup_dates in the future.
OUTLIERS — and the trap here
lifetime_value has 8 values above $2M against a $340 median. Before
you clip them: are they real whales or a currency/units bug? An
outlier that's a data error and an outlier that's your best customer
look identical in a boxplot. Check the source, don't just winsorize.
DISTRIBUTION RISK FOR TRAINING
region is 78% one value. A model trained on this won't generalize
off that region — that's a sampling problem no cleaning fixes, and
it's the finding most likely to bite you post-deployment.
REMEDIATION PLAN, ORDERED
1. Exclude the 47 impossible-date rows (errors, non-negotiable)
2. Normalize account_status casing
3. Decide last_purchase null semantics WITH a domain owner — don't
impute blind
4. Verify the 8 LTV outliers at source before any clipping
5. Flag the region skew to whoever owns the model's scope
Point me at the file and I'll run the real profile.About this skill
name: data-quality-auditor description: Use when Audit datasets for completeness, consistency, accuracy, and validity.
Data Quality Auditor
Audit datasets for completeness, consistency, accuracy, and validity. Profile data distributions, detect anomalies and outliers, surface structural issues, and produce an actionable remediation plan. Use when the user asks to check data quality, profile a dataset, hunt outliers or missing values, or validate data before analysis or model training.
What you get
- Public GitHub repo (alirezarezvani/claude-skills)
- the data-quality-auditor skill folder with SKILL.md. Part of a 337-skill / 30-agent / 70-command install.
Customize your output
- Fork the repo and adapt the skill's instructions and references to your workflow.
Example output
Activates automatically when your request matches Data Quality Auditor; chains with the other skills, agents, and commands in the collection.
Best for
Creators, builders, and teams using Claude Code.
SKILL.md preview
---
name: data-quality-auditor
description: Use this skill when checking data quality, profiling a dataset, hunting outliers or missing values, or validating data before analysis or training.
version: 1.0.0
category: Development / Engineering
author: AgentVolt
license: proprietary
tags:
- development
- engineering
---
# Data Quality Auditor
Profiles a dataset for completeness, consistency, accuracy, and validity, surfaces structural issues, and produces a concrete remediation plan.
## When to use
… (sign up to view the full skill)Featured in
More development skills
View all Development skills →Generate
Scaffold code, tests, and boilerplate from a short spec.
Performance Profiler
Systematic performance profiling for Node.js, Python, and Go applications.
Threat Detection
Use when hunting for threats in an environment, analyzing IOCs, or detecting behavioral anomalies in telemetry.
Agent Harness
Turns a domain folder of skills into a bounded agentic loop: compile a goal into a task plan, execute with the domain's tools, verify every task, retry within a budget.