Agent skill

Profiling Tables

by astronomer in astronomer/agents

Deep-dive data profiling for a specific table. An agent skill from astronomer/agents.

Apache-2.0Auto-check passedData & Analytics

Install Profiling Tables

skills CLI
$ npx skills add astronomer/agents --skill profiling-tables -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install astronomer/agents profiling-tables --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/astronomer/agents.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/profiling-tables .claude/skills/profiling-tables && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
profiling-tables
GitHub stars
451
Token cost
~964 tokens
SKILL.md length
276 words
Files
1
Skills in repo
34
Repo updated
First seen
Licence
Apache-2.0

At a glance

Deep-dive data profiling for a specific table. An agent skill from astronomer/agents.

  • Works in 7 steps: Basic Metadata → Size and Shape → Column-Level Statistics → …
  • The user asks to profile a table
  • SKILL.md covers Step 1: Basic Metadata, Step 2: Size and Shape, Step 3: Column-Level Statistics and Step 4: Cardinality Analysis, plus 3 more sections
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Profiling Tables is an agent skill from astronomer/agents. Deep-dive data profiling for a specific table. Use when the user asks to profile a table, wants statistics about a dataset, asks about data quality, or needs to understand a table's structure and content. Requires a table name.

Its SKILL.md is about 960 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Data & Analytics, covering Data cleaning, Statistics and Data analysis. The repository describes itself as: AI agent tooling for data engineering workflows. The licence is Apache-2.0.

When your agent uses it

  • The user asks to profile a table
  • Wants statistics about a dataset
  • Asks about data quality
  • Needs to understand a tables structure and content

Example prompts

  • “/profiling-tables”

Workflow steps

7 steps, taken from the step headings in SKILL.md.

  1. Basic Metadata
  2. Size and Shape
  3. Column-Level Statistics
  4. Cardinality Analysis
  5. Sample Data
  6. Data Quality Assessment
  7. Output Summary

What it can do on your machine

Read from SKILL.md and the folder at commit 486ee63. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md (its code samples are sql).

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Profiling Tables loads about 964 tokens when it runs. Until then it costs about 61 tokens; SKILL.md has 276 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~61
When it runs · the whole SKILL.md, loaded when a task matches
~964

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from astronomer/agents at commit 486ee63, republished under its Apache-2.0 licence (© astronomer). 276 words, ~964 tokens.

Download SKILL.mdSave it as .claude/skills/profiling-tables/SKILL.md (or your agent's skills folder).
name
profiling-tables
description
Deep-dive data profiling for a specific table. Use when the user asks to profile a table, wants statistics about a dataset, asks about data quality, or needs to understand a table's structure and content. Requires a table name.

Data Profile

Generate a comprehensive profile of a table that a new team member could use to understand the data.

Step 1: Basic Metadata

Query column metadata:

sql
SELECT COLUMN_NAME, DATA_TYPE, COMMENT
FROM <database>.INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = '<schema>' AND TABLE_NAME = '<table>'
ORDER BY ORDINAL_POSITION

If the table name isn't fully qualified, search INFORMATION_SCHEMA.TABLES to locate it first.

Step 2: Size and Shape

Run via run_sql:

sql
SELECT
    COUNT(*) as total_rows,
    COUNT(*) / 1000000.0 as millions_of_rows
FROM <table>

Step 3: Column-Level Statistics

For each column, gather appropriate statistics based on data type:

Numeric Columns
sql
SELECT
    MIN(column_name) as min_val,
    MAX(column_name) as max_val,
    AVG(column_name) as avg_val,
    STDDEV(column_name) as std_dev,
    PERCENTILE_CONT(0.5) WITHIN GROUP (ORDER BY column_name) as median,
    SUM(CASE WHEN column_name IS NULL THEN 1 ELSE 0 END) as null_count,
    COUNT(DISTINCT column_name) as distinct_count
FROM <table>
String Columns
sql
SELECT
    MIN(LEN(column_name)) as min_length,
    MAX(LEN(column_name)) as max_length,
    AVG(LEN(column_name)) as avg_length,
    SUM(CASE WHEN column_name IS NULL OR column_name = '' THEN 1 ELSE 0 END) as empty_count,
    COUNT(DISTINCT column_name) as distinct_count
FROM <table>
Date/Timestamp Columns
sql
SELECT
    MIN(column_name) as earliest,
    MAX(column_name) as latest,
    DATEDIFF('day', MIN(column_name), MAX(column_name)) as date_range_days,
    SUM(CASE WHEN column_name IS NULL THEN 1 ELSE 0 END) as null_count
FROM <table>

Step 4: Cardinality Analysis

For columns that look like categorical/dimension keys:

sql
SELECT
    column_name,
    COUNT(*) as frequency,
    ROUND(COUNT(*) * 100.0 / SUM(COUNT(*)) OVER(), 2) as percentage
FROM <table>
GROUP BY column_name
ORDER BY frequency DESC
LIMIT 20

This reveals:

  • High-cardinality columns (likely IDs or unique values)
  • Low-cardinality columns (likely categories or status fields)
  • Skewed distributions (one value dominates)

Step 5: Sample Data

Get representative rows:

sql
SELECT *
FROM <table>
LIMIT 10

If the table is large and you want variety, sample from different time periods or categories.

Step 6: Data Quality Assessment

Summarize quality across dimensions:

Completeness
  • Which columns have NULLs? What percentage?
  • Are NULLs expected or problematic?
Uniqueness
  • Does the apparent primary key have duplicates?
  • Are there unexpected duplicate rows?
Freshness
  • When was data last updated? (MAX of timestamp columns)
  • Is the update frequency as expected?
Validity
  • Are there values outside expected ranges?
  • Are there invalid formats (dates, emails, etc.)?
  • Are there orphaned foreign keys?
Consistency
  • Do related columns make sense together?
  • Are there logical contradictions?

Step 7: Output Summary

Provide a structured profile:

Overview

2-3 sentences describing what this table contains, who uses it, and how fresh it is.

Schema
ColumnTypeNulls%DistinctDescription
...............
Key Statistics
  • Row count: X
  • Date range: Y to Z
  • Last updated: timestamp
Data Quality Score
  • Completeness: X/10
  • Uniqueness: X/10
  • Freshness: X/10
  • Overall: X/10
Potential Issues

List any data quality concerns discovered.

3-5 useful queries for common questions about this data.

© astronomer, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in skills/profiling-tables of astronomer/agents.

Open the folder on GitHubat commit 486ee63

Compare with similar skills

Profiling Tables next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Profiling Tables compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Profiling Tables this skillastronomer/agents451—~964Automated safety check: PassApache-2.0
Code EngineeropenJiuwen-ai/sciencediscovery151—~2.8kAutomated safety check: PassApache-2.0
Data Analysisxiaoyuge886/aigc1981 repos~794Automated safety check: PassMIT
Data Explorerliangdabiao/claude-data-analysis-ultra-main290—~2.1kAutomated safety check: PassNone
Stat Edaasgard-ai-platform/skills241—~954Automated safety check: PassMIT
Data Researchermajiayu000/claude-skill-registry6661 repos~4.6kAutomated safety check: PassMIT

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Questions about Profiling Tables

What does Profiling Tables do?

Deep-dive data profiling for a specific table. An agent skill from astronomer/agents. Profiling Tables is an agent skill from astronomer/agents. Deep-dive data profiling for a specific table.

When should I use Profiling Tables?

Profiling Tables fits situations like: the user asks to profile a table; wants statistics about a dataset; asks about data quality; needs to understand a tables structure and content.

How do I install Profiling Tables in Claude Code?

Run `npx skills add astronomer/agents --skill profiling-tables -a claude-code`. Or copy the skill folder (skills/profiling-tables in astronomer/agents) into .claude/skills/profiling-tables in your project. Claude Code loads it when a task matches its description.

How do I install Profiling Tables in Codex?

Run `npx skills add astronomer/agents --skill profiling-tables -a codex`. Or copy the skill folder (skills/profiling-tables in astronomer/agents) into .agents/skills/profiling-tables in your project. Codex loads it when a task matches its description.

Can I use Profiling Tables in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add astronomer/agents --skill profiling-tables -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/profiling-tables, .gemini/skills/profiling-tables, .github/skills/profiling-tables and .opencode/skills/profiling-tables in your project.

What does Profiling Tables need to run?

SKILL.md names no scripts, command-line tools or credentials: Profiling Tables is instructions for the agent only.

Does Profiling Tables access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Profiling Tables safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Profiling Tables use?

Profiling Tables is published under the Apache-2.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Profiling Tables use?

About 964 tokens (SKILL.md is roughly 3.9k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Profiling Tables?

Skills that share tags, products or a category with Profiling Tables: Code Engineer (openJiuwen-ai/sciencediscovery, 151 stars), Data Analysis (xiaoyuge886/aigc, 198 stars), Data Explorer (liangdabiao/claude-data-analysis-ultra-main, 290 stars) and Stat Eda (asgard-ai-platform/skills, 241 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Profiling Tables?

astronomer (a GitHub organization) maintains it in astronomer/agents, which has 451 GitHub stars. The repository holds 34 skills in this directory. The repository was last updated on October 7, 2026.

Source: astronomer/agents on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.