Agent skill
tech-design-doc
Generate technical design documents with proper structure, diagrams, and implementation details. Default language is English unless user requests Chinese.
Install this agent skill to your Project
npx add-skill https://github.com/acking-you/myclaude-skills/tree/main/skills/tech-design-doc
SKILL.md
Technical Design Document Skill
When to Use
- Designing a new feature or system
- Documenting architecture decisions (ADR/RFC)
- Planning refactoring or optimization work
Execution Flow
1. Assess Complexity
| Level | Scope | Sections Required |
|---|---|---|
| Small | Single component, <100 LOC | TL;DR, Design, Implementation |
| Medium | Cross-component, API changes | + Background, Solution Analysis |
| Large | System-level, new service | Full template |
2. Gather Context
Before writing, explore the codebase:
- Identify affected components (grep/glob for related code)
- Read existing implementations and patterns
- Note dependencies and potential side effects
- Check for similar solutions already in codebase
3. Write Document
Follow the template structure below, scaled to complexity level.
4. Verify Before Handoff
- Problem clearly defined (what breaks if we do nothing?)
- Options compared with trade-offs (not just one solution)
- Decision rationale documented
- Diagrams illustrate key flows
- Implementation steps are concrete and actionable
- Risks identified with mitigations
Document Template
# [Feature/System Name] Technical Design
## TL;DR
- 3-5 bullets: problem, solution, key decisions, expected outcome
## Background (Medium/Large)
### Current State
- Existing behavior and limitations
### Problem Statement
- What breaks if we do nothing?
- Who is affected and how?
### Goals / Non-Goals
- Goals: what this design achieves
- Non-Goals: explicitly out of scope
## Solution Analysis (Medium/Large)
### Option 1: [Name]
Pros: ...
Cons: ...
### Option 2: [Name]
Pros: ...
Cons: ...
### Comparison
| Criteria | Option 1 | Option 2 |
|----------|----------|----------|
| Performance | ... | ... |
| Complexity | ... | ... |
### Recommendation
Selected: Option X
Rationale: [why]
## Detailed Design
### Architecture
[Mermaid diagram - see examples below]
### Component Design
- Responsibilities
- Interfaces
- Dependencies
### Data Model (if applicable)
[Schema or structure]
### API Design (if applicable)
[Endpoints, request/response]
## Implementation Plan
### Phase 1: [Name]
- [ ] Task 1
- [ ] Task 2
### Migration Strategy (if applicable)
## Risk Assessment
| Risk | Probability | Impact | Mitigation |
|------|-------------|--------|------------|
| ... | High/Med/Low | High/Med/Low | ... |
## References
- Related docs, external resources
Mermaid Diagram Examples
Architecture (flowchart):
flowchart TD
A[Client] --> B[API Gateway]
B --> C[Service]
C --> D[(Database)]
Sequence:
sequenceDiagram
Client->>Server: Request
Server->>DB: Query
DB-->>Server: Result
Server-->>Client: Response
State:
stateDiagram-v2
[*] --> Pending
Pending --> Processing: start
Processing --> Done: complete
Processing --> Failed: error
Handling Feedback
When user requests changes:
- Understand which section needs revision
- Update only affected sections
- Ensure changes don't contradict other sections
- Re-verify the checklist items related to changes
Output Location
- Check if project has
docs/,ai_docs/, ordesign/directory - Ask user if location is unclear
- Use descriptive filename:
design-[feature-name].md
Recommended Agent Skills
Expand your agent's capabilities with these related and highly-rated skills.
github-wrapped
Generate a verifiable GitHub Wrapped year-in-review as a single-file HTML (raw gh API JSON saved, Python-built dataset embedded), with a Bilibili-style narrative, smooth transitions, and mobile-friendly paged mode. Requires gh CLI to be authenticated.
codex-session-history
Search Codex local session history stored in SQLite and session_index.jsonl. Use this skill when the user wants to list, search, filter, or inspect locally saved Codex sessions by session id, provider, time range, preview text, thread name, or archived status.
tech-impl-doc
Write precise technical implementation docs (developer or user) with clear structure, accurate flows, render-safe Mermaid diagrams, and audience-appropriate detail; avoid boilerplate; include a meaningful Code Index for developer docs.
gemini-image
Generate images using AI when user wants to create pictures, draw, paint, or generate artwork. Supports text-to-image and image-to-image generation.
excalidraw
Generate hand-drawn style diagrams (architecture, flowcharts, system design) as .excalidraw.json files. Use when user wants diagrams, mentions Excalidraw, or needs Mermaid-to-visual conversion.
research
Structured web research with multi-source validation. Output reports with complete citation links. Focus on key results, verify information quality.
Didn't find tool you were looking for?