database-schema-documentation

database-schema-documentation is a skill for Claude Code, Codex from aj-geddes/useful-ai-prompts. It costs 37 tokens per session (567 once invoked), scanned A, original, MIT.

A way to record how a database is organized, including its tables, fields, indexes, rules, and relationships. It can also describe an ERD, a diagram showing how database entities are connected.

In plain words
What is it for?
It helps create schema documentation, ERD diagrams, data dictionaries, table references, and migration notes.
Why use it?
It gives developers a shared reference for understanding existing data and reduces confusion when changing or integrating with a database.

Skill for Claude CodeCodex

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

Good fit It helps create schema documentation, ERD diagrams, data dictionaries, table references, and migration notes.

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Install with agentmods
npx agentmods add skills/aj-geddes/useful-ai-prompts/database-schema-documentation
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 aj-geddes/useful-ai-prompts --skill database-schema-documentation
Clone the repo
git clone --depth 1 https://github.com/aj-geddes/useful-ai-prompts

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 database-schema-documentation

README.md
[![agentmods](https://agentmods.dev/badge/skills/aj-geddes/useful-ai-prompts/database-schema-documentation/github.svg)](https://agentmods.dev/skills/aj-geddes/useful-ai-prompts/database-schema-documentation)
Your own site
<a href="https://agentmods.dev/skills/aj-geddes/useful-ai-prompts/database-schema-documentation"><img src="https://agentmods.dev/badge/skills/aj-geddes/useful-ai-prompts/database-schema-documentation/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 database-schema-documentation

Your own site · 80×15
<a href="https://agentmods.dev/skills/aj-geddes/useful-ai-prompts/database-schema-documentation"><img src="https://agentmods.dev/badge/skills/aj-geddes/useful-ai-prompts/database-schema-documentation.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 37 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 567 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. Third-party audits
  • Socket pass 18 Mar 2026
  • Snyk pass 5 Mar 2026
How audits are shown
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 $0.00037 $0.00567
Opus 5 $0.00018 $0.00283
Sonnet 5 $0.00007 $0.00113
Haiku 4.5 $0.00004 $0.00057

Measured 9d ago against content hash ac904d8b2bb0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

database-schema-documentation 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 9d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/validate-schema.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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/database-schema-documentation/SKILL.md · 100 lines

What it actually says

Database Schema Documentation

Table of Contents

Overview

Create comprehensive database schema documentation including entity relationship diagrams (ERD), table definitions, indexes, constraints, and data dictionaries.

When to Use

  • Database schema documentation
  • ERD (Entity Relationship Diagrams)
  • Data dictionary creation
  • Table relationship documentation
  • Index and constraint documentation
  • Migration documentation
  • Database design specs

Quick Start

Minimal working example:

# Database Schema Documentation

**Database:** PostgreSQL 14.x
**Version:** 2.0
**Last Updated:** 2025-01-15
**Schema Version:** 20250115120000

## Overview

This database supports an e-commerce application with user management, product catalog, orders, and payment processing.

## Entity Relationship Diagram

```mermaid
erDiagram
    users ||--o{ orders : places
    users ||--o{ addresses : has
    users ||--o{ payment_methods : has
    orders ||--|{ order_items : contains
    orders ||--|| payments : has
    products ||--o{ order_items : includes
    products }o--|| categories : belongs_to
    products ||--o{ product_images : has
    products ||--o{ inventory : tracks

// ... (see reference guides for full implementation)
```

## Reference Guides

Detailed implementations in the `references/` directory:

| Guide | Contents |
|---|---|
| [users](references/users.md) | users |
| [products](references/products.md) | products |
| [orders](references/orders.md) | orders |
| [order_items](references/orderitems.md) | order_items |
| [Enum Types](references/enum-types.md) | Enum Types, JSONB Structures |

## Best Practices

### ✅ DO

- Document all tables and columns
- Create ERD diagrams
- Document indexes and constraints
- Include sample data
- Document foreign key relationships
- Show JSONB field structures
- Document triggers and functions
- Include migration scripts
- Specify data types precisely
- Document performance considerations

### ❌ DON'T

- Skip constraint documentation
- Forget to version schema changes
- Ignore performance implications
- Skip index documentation
- Forget to document enum values
Files

What ships with it

7 files 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. 9d ago First seen · 100 lines · 37 tokens per session scan A ac904d8b2bb0

Subscribe to this mod's changes

database-schema-documentation is a skill published in the GitHub repository aj-geddes/useful-ai-prompts (338 stars, last pushed 6mo ago), licensed MIT. It adds 37 tokens to every session and 567 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 2026-09-03.