10-spec-first

10-spec-first is a cursor rule for Cursor from vaquarkhan/data-engineering-agent-skills. It costs 10 tokens per session (93 once invoked), scanned A, original, MIT.

A set of rules requiring a written specification before building new data products or making major data-pipeline changes. The specification records success criteria and unanswered questions.

In plain words
What is it for?
Use it for new pipelines, schema changes, major data models, and operationally important work that needs a plan and agreed requirements first.
Why use it?
It prevents coding from starting before the intended result and important decisions are clear.

Cursor rule for Cursor

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 rules/vaquarkhan/data-engineering-agent-skills/10-spec-first
Clone the repo
git clone --depth 1 https://github.com/vaquarkhan/data-engineering-agent-skills

Made for: Cursor.

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 10-spec-first

README.md
[![agentmods](https://agentmods.dev/badge/rules/vaquarkhan/data-engineering-agent-skills/10-spec-first.svg)](https://agentmods.dev/rules/vaquarkhan/data-engineering-agent-skills/10-spec-first)
Your own site
<a href="https://agentmods.dev/rules/vaquarkhan/data-engineering-agent-skills/10-spec-first"><img src="https://agentmods.dev/badge/rules/vaquarkhan/data-engineering-agent-skills/10-spec-first.svg" alt="Measured on agentmods" height="20"></a>
Per session 10 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 93 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 $0.00010 $0.00093
Opus 5 $0.00005 $0.00046
Sonnet 5 $0.00002 $0.00019
Haiku 4.5 $0.00001 $0.00009

Measured 5d ago against content hash 0561dc4ed67f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

10-spec-first 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.

.cursor/rules/10-spec-first.mdc · 15 lines

What it actually says

Spec First

For new pipelines, schema changes, major modeling work, or operationally significant changes:

  • use skills/data-specification/SKILL.md
  • use skills/pipeline-planning-and-task-breakdown/SKILL.md
  • use templates from templates/
  • avoid coding until success criteria and open questions are explicit
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 · 15 lines · 10 tokens per session scan A 0561dc4ed67f

Subscribe to this mod's changes

10-spec-first is a cursor rule published in the GitHub repository vaquarkhan/data-engineering-agent-skills (40 stars, last pushed 2mo ago), licensed MIT. It adds 10 tokens to every session and 93 once invoked, about $0.0001 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.