data-dictionary-creator

data-dictionary-creator is a skill for Claude Code, Codex from danielrosehill/Claude-Data-Analyst-plugin. It costs 62 tokens per session (704 once invoked), scanned A, original, MIT.

A data dictionary is a reference that explains what each dataset column means, including its type, units, allowed values, and whether it can be empty. This skill creates one by combining automatic measurements with the user's description.

In plain words
What is it for?
Use it to document CSV, Parquet, or Excel files as Markdown, CSV, or JSON, including column statistics, examples, missing values, and meanings.
Why use it?
It turns an unfamiliar dataset into documented information that people can understand and use consistently.

Skill for Claude CodeCodex

Part of the claude-data-analyst plugin — 14 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/danielrosehill/claude-data-analyst-plugin/data-dictionary-creator
Any agent
npx skills add danielrosehill/Claude-Data-Analyst-plugin --skill data-dictionary-creator
Clone the repo
git clone --depth 1 https://github.com/danielrosehill/Claude-Data-Analyst-plugin

Made for: Claude Code, Codex.

Or install claude-data-analyst, the plugin that ships this one along with the rest of its 14 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-dictionary-creator

README.md
[![agentmods](https://agentmods.dev/badge/skills/danielrosehill/claude-data-analyst-plugin/data-dictionary-creator.svg)](https://agentmods.dev/skills/danielrosehill/claude-data-analyst-plugin/data-dictionary-creator)
Your own site
<a href="https://agentmods.dev/skills/danielrosehill/claude-data-analyst-plugin/data-dictionary-creator"><img src="https://agentmods.dev/badge/skills/danielrosehill/claude-data-analyst-plugin/data-dictionary-creator.svg" alt="Measured on agentmods" height="20"></a>
Per session 62 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 704 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 $0.00062 $0.00704
Opus 5 $0.00031 $0.00352
Sonnet 5 $0.00012 $0.00141
Haiku 4.5 $0.00006 $0.00070

Measured 4d ago against content hash a05615c3394e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

data-dictionary-creator 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 4d 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/data-dictionary-creator/SKILL.md · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Data Dictionary Creator

Produce a data dictionary by merging schema inspection with the user's semantic description of the dataset.

Inputs

  • Path to a dataset file or folder.
  • The user's description of the dataset: what it represents, how it was collected, what each column means (can be partial — infer the rest).
  • Optional: output format (markdown default, csv, or json).
  • duckdb -c "DESCRIBE SELECT * FROM '<file>'" — fast schema + inferred types.
  • csvstat — null counts, uniqueness, min/max per column.
  • uv run --with pandas python -c '...' — for dtype coercion and sampling.

Procedure

Step 1 — Auto-profile every column

For each column, collect:

  • Inferred data type (int, float, string, date, boolean, category)
  • Null count and percentage
  • Unique count (and full value list if <20 distinct)
  • Min / max / mean (numeric) or top-5 modes (categorical)
  • Sample values (3 random non-null)

Step 2 — Merge with the user's description

Parse the user's description and map sentences to columns. For each column, fill:

  • Name (as in the file)
  • Display name / human-readable label
  • Description — one-sentence semantic meaning
  • Type
  • Unit (currency code, SI unit, %, count, etc.)
  • Allowed values — enumerated list if categorical with small cardinality
  • Nullable — yes/no and what a null means (missing vs. not-applicable)
  • Source — where this field originated if the user mentioned it
  • PII — none / direct / quasi-identifier (cross-check with pii-flag heuristics)
  • Notes — caveats, known issues, derivation formulas

If a column isn't covered by the user's description, mark the Description field as [NEEDS REVIEW] rather than guessing, and list these at the end for user confirmation.

Step 3 — Add dataset-level metadata

At the top of the dictionary:

  • Dataset name and path
  • Purpose (from user description)
  • Row count, column count
  • Primary key(s) — infer from uniqueness; ask if ambiguous
  • Collection period if derivable from timestamp columns
  • Last modified timestamp

Read the full file on GitHub · 85 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. 4d ago First seen · 85 lines · 62 tokens per session scan A a05615c3394e

Subscribe to this mod's changes

data-dictionary-creator is a skill published in the GitHub repository danielrosehill/Claude-Data-Analyst-plugin (11 stars, last pushed 4mo ago), licensed MIT. It adds 62 tokens to every session and 704 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 2026-08-30.

Related

Other skills, from other repositories