Entity Model

What it does

When your agent uses it

• The user asks to create an entity model
• Design a data model
• Define database schema
• Mentions entity-relationship diagram

Example prompts

• “create an entity model”
• “design a data model”
• “draw an ERD”
• “/entity-model”

Workflow steps

3 steps, taken from the first numbered list in SKILL.md.

1. 1A ### heading with the entity name in UPPERCASE (UPPER_SNAKE_CASE, e.g. ### ROOM_TYPE — never ### Room Type or ## Entity: Room Type)
2. 2One sentence description
3. 3An attribute table with exactly these 5 columns in this order: Attribute, Description, Data Type, Length/Precision, Validation Rules

What it can do on your machine

Read from SKILL.md and the folder at commit d25bf91. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  No scripts in the folder and no shell commands in SKILL.md (its code samples are markdown).

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Links to these hosts (documentation or services it may open):

  • unifiedprocess.ai

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Entity Model loads about 1.9k tokens when it runs, and up to ~2.3k if it reads all its reference files. Until then it costs about 191 tokens; SKILL.md has 714 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~191

When it runs · the whole SKILL.md, loaded when a task matches

~1.9k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~2.3k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from AI-Unified-Process/marketplace at commit d25bf91, republished under its Apache-2.0 licence (© AI-Unified-Process). 714 words, ~1,893 tokens.

name

entity-model

description

Creates entity model documents with Mermaid.js ER diagrams and attribute tables defining entities, relationships, data types, and validation rules. Use when the user asks to "create an entity model", "design a data model", "draw an ERD", "define database schema", "model entities", or mentions entity-relationship diagram, ER diagram, database design, or data modeling. Also trigger whenever the task is to produce, write, or design an entity model or data model document (e.g. docs/entity_model.md) from a requirements catalog — including phrasings like "data model design", "the team needs an entity model before development", or a request to document entities with attributes, data types, precision, and validation or cross-attribute constraints.

<!--
Copyright 2025-2026 Simon Martinelli and the AI Unified Process contributors.
Part of the AI Unified Process — https://unifiedprocess.ai
Licensed under the Apache License, Version 2.0. See LICENSE and NOTICE.
-->

# Entity Model

## Entity Relationship Diagram

```mermaid
erDiagram
    ROOM_TYPE ||--o{ ROOM : "categorizes"
    GUEST ||--o{ RESERVATION : "makes"

#### Constraints

- Check-out date must be after check-in date.
- The number of guests must not exceed the room type's capacity.

© AI-Unified-Process, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 1 other file (references) in aiup-core/skills/entity-model of AI-Unified-Process/marketplace.

• SKILL.md
• references/REFERENCE.md

Open the folder on GitHubat commit d25bf91