data-analyst

A method for answering data questions by checking the meaning of fields and metrics before writing a query, then validating the result with offline tests. A semantic layer is the project's reference for what its data means.

In plain words
What is it for?
Use it to answer questions against structured data when correctness depends on business definitions, metric rules, table relationships, or known data limitations.
Why use it?
A query can run successfully and still return the wrong number if its tables, fields, filters, or definitions are misunderstood.

Skill for Claude CodeCodex

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/caprista/karvyloop/data-analyst
Any agent
npx skills add Caprista/KarvyLoop --skill data-analyst
Clone the repo
git clone --depth 1 https://github.com/Caprista/KarvyLoop

Made for: Claude Code, Codex.

Per session 48 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 958 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 $0.00048 $0.00958
Opus 5 $0.00024 $0.00479
Sonnet 5 $0.00010 $0.00192
Haiku 4.5 $0.00005 $0.00096

Measured 2d ago against content hash 34103345931b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

data-analyst 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 2d 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.

karvyloop/system_skills/data-analyst/SKILL.md · 75 lines

How it starts

The opening of the file, as written. The whole thing — 75 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Data Analyst (system template)

Data is not software. A query can run with zero errors and still return the wrong number — and there is no compiler or test suite that catches it, because correctness lives in the data's meaning, which sits outside the code. So the model writing the query is the easy 10%; the other 90% is context (the semantic layer) and verification. This skill is a method, not an answer.

The accountability rule

You (atom) answer to the role; the role answers to the human. A confident wrong number is worse than "I don't know" — it spends trust you cannot get back. When in doubt, return the uncertainty with the evidence, never a guessed number.

Procedure — do not skip steps

  1. Anchor in the semantic layer first — never guess what a column means. Before writing any query, read the user's data definitions (which table/column means what, how each metric is defined, its grain, default filters, known caveats). See references/semantic-layer.template.md for the shape; the filled-in copy lives in the user's own space and is human-owned. If a definition is missing or ambiguous, ask — do not invent one (auto-generated definitions are net-negative).

  2. Disambiguate the question against real entities. The #1 failure mode is concept↔entity ambiguity ("active users" — by which definition? which date grain? which timezone?). Restate the question in the semantic layer's own terms and confirm before querying.

  3. Find the right data, then write the smallest query that answers it. Prefer the canonical/governed table named in the semantic layer over whatever you find first. Record exactly which tables, columns, and filters you used.

  4. Validate before you trust — this is the gate, not a nicety.

    • Run against the offline test set of known question→answer pairs for this data, if one exists. A query that breaks a known-good answer is wrong until proven otherwise.
    • Sanity-check the result: order of magnitude, row counts, null rates, date range, obvious double-counting. A number that "looks off" gets investigated, not reported.
    • Check staleness: is the data fresh enough to answer this question?

Read the full file on GitHub · 75 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. 2d ago First seen · 75 lines · 48 tokens per session scan A 34103345931b

Subscribe to this mod's changes

data-analyst is a skill published in the GitHub repository Caprista/KarvyLoop (10 stars, last pushed 6d ago), licensed MIT. It adds 48 tokens to every session and 958 once invoked, about $0.0002 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 2026-08-31.