Azure Architecture Decision Records (ADR) Skill

Create formal Architecture Decision Records that document significant infrastructure decisions with Azure-specific context, WAF pillar analysis, and implementation guidance.

When to Use This Skill

Output Format

ADRs are saved to the project's agent-output folder:

agent-output/{project}/
├── 03-des-adr-0001-{short-title}.md    # Design phase ADRs
└── 07-ab-adr-0001-{short-title}.md     # As-built phase ADRs

Naming Convention

• •Prefix: 03-des-adr- (design) or 07-ab-adr- (as-built)
• •Number: 4-digit sequence (0001, 0002, etc.)
• •Title: Lowercase with hyphens (e.g., use-cosmos-db-for-state)

ADR Template Structure

# ADR-{NNNN}: {Decision Title}

> Status: Proposed | Accepted | Deprecated | Superseded
> Date: {YYYY-MM-DD}
> Deciders: {team/person}

## Context

What is the issue that we're seeing that is motivating this decision or change?

## Decision

What is the change that we're proposing and/or doing?

## Alternatives Considered

| Option   | Pros | Cons | WAF Impact                     |
| -------- | ---- | ---- | ------------------------------ |
| Option A | ...  | ...  | Security: +, Cost: -           |
| Option B | ...  | ...  | Reliability: +, Performance: + |

## Consequences

### Positive

- List of positive outcomes

### Negative

- List of trade-offs or risks

### Neutral

- List of neutral observations

## WAF Pillar Analysis

| Pillar      | Impact | Notes |
| ----------- | ------ | ----- |
| Security    | ↑/↓/→  | ...   |
| Reliability | ↑/↓/→  | ...   |
| Performance | ↑/↓/→  | ...   |
| Cost        | ↑/↓/→  | ...   |
| Operations  | ↑/↓/→  | ...   |

## Compliance Considerations

- List any regulatory or compliance implications

## Implementation Notes

- Key implementation details or constraints

Example Prompts

Design Phase ADR

Create an ADR documenting our decision to use Azure Cosmos DB
instead of Azure SQL for the e-commerce catalog service.
Consider WAF implications and cost trade-offs.

As-Built ADR

Document the architectural decision we made during implementation
to use Azure Front Door instead of Application Gateway.
Include the performance testing results that informed this choice.

From Assessment

Use the azure-adr skill to document the database decision from
the architecture assessment above as a formal ADR.

Integration with Workflow

Best Practices

1. •One decision per ADR - Keep ADRs focused on a single decision
2. •Include alternatives - Always document what was considered and rejected
3. •Map to WAF pillars - Show impact on each Well-Architected pillar
4. •Link to requirements - Reference the requirement that drove the decision
5. •Keep it concise - ADRs should be readable in 5 minutes

Common ADR Topics

What This Skill Does NOT Do

• •❌ Generate Bicep or Terraform code
• •❌ Create architecture diagrams (use azure-diagrams skill)
• •❌ Deploy resources (use deploy agent)
• •❌ Create implementation plans (use bicep-plan agent)

Workflow Integration

This skill produces artifacts in Step 3 (design) or Step 7 (as-built).

Artifact Suffix Rules

1. •When called from Architect → use 03-des-adr- prefix
2. •When called after deployment (Step 6) → use 07-ab-adr- prefix
3. •When called standalone:
   • •Design/proposal/planning language → use 03-des-adr-
   • •Deployed/implemented/current state language → use 07-ab-adr-

Important: The 07-ab-adr- ADR may differ from 03-des-adr- if implementation required changes. Document any deviations in the "Implementation Notes" section.

Generation Workflow

Follow these steps when creating ADRs:

1. •Gather Information - Collect decision context, alternatives, stakeholders
2. •Determine Number - Check existing ADRs in agent-output/{project}/ for next sequence
3. •Determine Phase - Design (03-des-) or As-Built (07-ab-) based on context
4. •Generate Document - Create ADR following template structure
5. •Include WAF Analysis - Map decision impact to all 5 WAF pillars
6. •Document Alternatives - List at least 2-3 alternatives with rejection reasons

Quality Checklist

Before finalizing the ADR, verify:

• • ADR number is sequential and correct
• • File name follows naming convention ({step}-adr-NNNN-{title-slug}.md)
• • Status is set appropriately (Proposed for design, Accepted for as-built)
• • Date is in YYYY-MM-DD format
• • Context clearly explains the problem/opportunity
• • Decision is stated clearly and unambiguously
• • At least 1 positive consequence documented
• • At least 1 negative consequence documented
• • At least 1 alternative documented with rejection reasons
• • WAF pillar analysis includes all 5 pillars
• • Implementation notes provide actionable guidance

Guardrails

DO

• •✅ Create ADR files in agent-output/{project}/
• •✅ Use step-prefixed filenames (03-des-adr-* or 07-ab-adr-*)
• •✅ Use 4-digit sequential numbering (0001, 0002, etc.)
• •✅ Include WAF pillar analysis for every ADR
• •✅ Document at least 2-3 alternatives considered
• •✅ Be honest about both benefits and drawbacks
• •✅ Keep ADRs focused on a single decision
• •✅ Use specific, measurable consequences

DO NOT

• •❌ Use vague decision statements ("We decided to use a database")
• •❌ Skip alternatives section or use "none considered"
• •❌ List only positive consequences
• •❌ Skip WAF pillar analysis
• •❌ Use placeholder text like "TBD" or "Insert here"
• •❌ Create ADRs that cover multiple unrelated decisions
• •❌ Use generic implementation notes ("Deploy to Azure")

Patterns to Avoid