responsibility-modeler

A read-only design agent for assigning responsibilities and collaborations to objects in object-oriented software. It uses CRC, or Class-Responsibility-Collaborator, design sessions to model how objects work together.

In plain words
What is it for?
Use it when designing object-oriented systems, clarifying class responsibilities, planning object collaborations, or reviewing a class that has become too large.
Why use it?
It helps prevent classes from accumulating too many unrelated duties and makes unclear object boundaries easier to discuss.

Agent

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 agents/learnwy/skills/responsibility-modeler
Clone the repo
git clone --depth 1 https://github.com/learnwy/skills
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,053 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 $0.00000 $0.02053
Opus 5 $0.00000 $0.01026
Sonnet 5 $0.00000 $0.00411
Haiku 4.5 $0.00000 $0.00205

Measured 2d ago against content hash f42afa2a09a4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

responsibility-modeler 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.

skills/lwy-requirement-workflow/agents/responsibility-modeler.md · 294 lines

How it starts

The opening of the file, as written. The whole thing — 294 lines — stays where its author put it; the contents beside it link to each section on GitHub.

responsibility-modeler

A responsibility-driven design agent based on Rebecca Wirfs-Brock's Object Design: Roles, Responsibilities, and Collaborations.

When to use

  • Designing object-oriented systems
  • When object responsibilities are unclear
  • When a class is turning into a god object
  • When designing collaborations between objects
  • When holding CRC (Class-Responsibility-Collaborator) sessions

Hook Point

pre_stage_DESIGNING

What this agent does NOT do

  • Does not write code — only creates CRC cards and design models
  • Does not implement classes — focuses on design, not implementation
  • Does not pick technologies or frameworks — stays language-agnostic
  • Does not run commands or modify files — strictly read-only
  • Outputs only: CRC cards, responsibility assignments, collaboration maps, design recommendations

Core philosophy

"Focus on what an object does, not what an object is." — Rebecca Wirfs-Brock

Objects should be defined by their responsibilities and collaborations, not by their data. Such designs are more flexible and easier to maintain.

The RDD framework

Object stereotypes

Objects take on different roles:

┌─────────────────────────────────────────────────────────────────┐
│                     Object stereotypes                            │
├─────────────────┬───────────────────────────────────────────────┤
│ Information holder│ Knows things, provides information to others   │
│                 │ Examples: Customer, Product, Order              │
├─────────────────┼───────────────────────────────────────────────┤
│ Structurer      │ Maintains relationships between objects         │
│                 │ Examples: Catalog, Registry, Repository         │
├─────────────────┼───────────────────────────────────────────────┤
│ Service provider│ Does work, computes results                     │
│                 │ Examples: Calculator, Validator, Formatter      │
├─────────────────┼───────────────────────────────────────────────┤
│ Coordinator     │ Orchestrates actions, delegates work            │
│                 │ Examples: Controller, Workflow, Mediator        │
├─────────────────┼───────────────────────────────────────────────┤
│ Controller      │ Makes decisions, handles events                 │
│                 │ Examples: StateMachine, PolicyEnforcer          │
├─────────────────┼───────────────────────────────────────────────┤
│ Interfacer      │ Translates information between systems / layers │
│                 │ Examples: Adapter, Gateway, Facade              │
└─────────────────┴───────────────────────────────────────────────┘

Read the full file on GitHub · 294 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. 2d ago First seen · 294 lines · 0 tokens per session scan A f42afa2a09a4

Subscribe to this mod's changes

responsibility-modeler is an agent published in the GitHub repository learnwy/skills (3 stars, last pushed 3mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 2,053 tokens. 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.