data-analysis

data-analysis is a skill for Claude Code, Codex from damianvtran/local-operator. It costs 45 tokens per session (623 once invoked), scanned A, original, MIT.

A careful process for exploring datasets by checking their shape, types, missing values, duplicates, units, ranges, and timestamps before calculating results.

In plain words
What is it for?
Use it to profile datasets, compute metrics, investigate patterns, and produce results that others can recheck.
Why use it?
It reduces errors caused by bad data, unclear units, duplicate records, missing values, or unreproducible queries.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to profile datasets, compute metrics, investigate patterns, and produce results that others can recheck.

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Install with agentmods
npx agentmods add skills/damianvtran/local-operator/data-analysis
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 damianvtran/local-operator --skill data-analysis
Clone the repo
git clone --depth 1 https://github.com/damianvtran/local-operator

Made for: Claude Code, Codex.

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-analysis

README.md
[![agentmods](https://agentmods.dev/badge/skills/damianvtran/local-operator/data-analysis/github.svg)](https://agentmods.dev/skills/damianvtran/local-operator/data-analysis)
Your own site
<a href="https://agentmods.dev/skills/damianvtran/local-operator/data-analysis"><img src="https://agentmods.dev/badge/skills/damianvtran/local-operator/data-analysis/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-analysis

Your own site · 80×15
<a href="https://agentmods.dev/skills/damianvtran/local-operator/data-analysis"><img src="https://agentmods.dev/badge/skills/damianvtran/local-operator/data-analysis.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 45 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 623 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 $0.00045 $0.00623
Opus 5.5 $0.00018 $0.00249
Sonnet 5.5 $0.00009 $0.00125
Haiku 4.5 $0.00005 $0.00062

Measured 5d ago against content hash 67c8d23cbff9, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

data-analysis 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 5d 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.

local_operator/skills/builtin/data-analysis/SKILL.md · 54 lines

How it starts

The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Data analysis

Numbers that survive scrutiny: profile first, keep queries reproducible, carry provenance, sanity-check the result.

Profile before trust

Check Why it matters
Shape: rows, columns, time range Know what you have before asking questions of it
Types and units per column A text date, or cents read as dollars, corrupts every downstream number
Keys and duplicates Duplicate keys silently change every aggregate
Missingness per column Null-heavy columns change what a rate means
Distributions and ranges Outliers and impossible values (negative ages, future dates) surface here
Timezone and calendar of timestamps Day boundaries move with zones

Keep the profile as a small set of queries you can rerun, not ad-hoc typing.

Reproducible queries

  • Keep the exact query behind every number in the report. A number nobody can re-derive is a rumour.
  • Deterministic: pin the snapshot or time window, make ordering explicit before any limit, and avoid "latest row" ambiguity.
  • Work in steps; save intermediates. After changing an input, rerun the step rather than mentally adjusting its output.

Guard silent joins and filters

  • Count rows before and after every join. An inner join on an incomplete key drops rows without an error.
  • Check filter semantics: inclusive or exclusive bounds, null membership, timezone edges. Apply each filter once.
  • State the population: "of the 4,210 rows matching X" beats "of the data".

Provenance and checks

  • Every reported number carries its source (table, snapshot), filter, and derivation. Derive it, or say where it came from.
  • Reconcile: totals equal the sum of their parts; an independent cut of the same data reproduces the number.
  • Units on everything: counts, rates, currency. Percentages name their denominator. Magnitudes are checked against expectation; a 1000x jump is a units or join error until proven otherwise.
  • Small n: below your stated threshold, report the count, not a rate. "60% (n=5)" misleads; "3 of 5" does not.

Read the full file on GitHub · 54 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. 5d ago First seen · 54 lines · 45 tokens per session scan A 67c8d23cbff9

Subscribe to this mod's changes

data-analysis is a skill published in the GitHub repository damianvtran/local-operator (218 stars, last pushed today), licensed MIT. It adds 45 tokens to every session and 623 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 2026-10-11.

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