technical-design-doc

Documents

Generates clear technical design documents with architecture, trade-offs, and rollout plans.

QUICK START

How to use this skill

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Review the proposed files and risks before you approve installation.

Prompt to paste

I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/majiayu000/claude-skill-registry/blob/HEAD/skills/data/technical-design-doc/SKILL.md

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First, summarize what it does, its dependencies, license status if identifiable, and any risks. Show the exact files you propose to add under .agents/skills/technical-design-doc/. Do not write files or run scripts until I approve.

After I approve, install the complete skill folder, including required referenced files, into that project location. Verify it is discoverable, then tell me its actual invocation name and how to use it. Do not claim it is installed until you have verified it.

Copying this prompt does not install or run the skill. Review third-party files before use. Codex skill guide

Technical Design Document Creator

Purpose

Use this skill to create design docs that:

Align stakeholders on what is being built and why.
Capture architecture and trade-offs explicitly.
Provide a durable reference for implementation and future changes.

When to Use

Cross-team or cross-service changes.
New user-facing features with non-trivial backend impact.
Data model changes, migrations, and new storage systems.
Major performance, reliability, or security projects.

Design Doc Structure

A good design doc should cover:

Overview
- One-paragraph summary of the problem and proposed solution.
- Expected impact at a high level.
Background and Context
- Current behavior and pain points.
- Relevant metrics, incidents, or user feedback.
- Links to prior designs or ADRs.
Goals and Non-Goals
- Goals: What success looks like.
- Non-goals: Explicitly out-of-scope aspects to prevent scope creep.
Requirements and Constraints
- Functional requirements.
- Non-functional: performance, availability, security, privacy, compliance, cost, deadlines.
Proposed Solution
- Architecture diagrams and component overviews.
- Data flow and control flow (sequence diagrams where useful).
- Key algorithms or logic at a high level.
Alternatives Considered
- Briefly describe 2–3 options and why they were rejected.
- Include “do nothing” when relevant.
Impact Analysis
- On existing systems, APIs, clients, and data.
- Operational impact: on-call, runbooks, observability.
- Risks and mitigations.
Testing and Validation
- Unit, integration, and end-to-end testing strategy.
- Load/performance testing plans.
- Rollback and failure drills, if applicable.
Rollout Plan
- Milestones and phases.
- Feature flagging or staged rollout strategy.
- Monitoring during rollout; success criteria.
Open Questions and Future Work
- Areas needing further exploration.
- Potential follow-ups that are explicitly out of the current scope.

Usage Guidance

Optimize for clarity over completeness. If a section is not applicable, say why.
Draw diagrams where they clarify non-trivial flows or boundaries.
Keep the document living: update when significant decisions or constraints change.

Examples of Good Prompts

“Create a full design doc using this template for the following feature description.”
“Given this high-level idea, flesh it out into a design doc with at least two alternative solutions.”
“Review this existing design doc using the template; identify missing sections and key risks.”