PR Finalize

Ensures PR title and description accurately reflect the implementation, and performs a code review for best practices before merge.

Standalone skill - Can be used on any PR, not just PRs reviewed by the pr-review skill.

Two-Phase Workflow

1. Title & Description Review - Verify PR metadata matches implementation
2. Code Review - Review code for best practices and potential issues

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🚨 CRITICAL RULES

1. NEVER Approve or Request Changes

AI agents must NEVER use --approve or --request-changes flags.

Action	Allowed?	Why
gh pr review --approve	❌ NEVER	Approval is a human decision
gh pr review --request-changes	❌ NEVER	Blocking PRs is a human decision

2. NEVER Post Comments Directly

This skill is ANALYSIS ONLY. Never post comments using gh commands.

Action	Allowed?	Why
gh pr review --comment	❌ NEVER	Review-PR.ps1 handles posting via scripts
gh pr comment	❌ NEVER	Review-PR.ps1 handles posting via scripts
Analyze and report findings	✅ YES	This is the skill's purpose

Correct workflow:

1. This skill: Analyze PR, produce findings and write to pr-finalize-summary.md
2. Review-PR.ps1 calls post-pr-finalize-comment.ps1 to post the summary

Only humans control when comments are posted. Your job is to analyze and present findings.

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Phase 1: Title & Description

Core Principle: Preserve Quality

Review existing description BEFORE suggesting changes. Many PR authors write excellent, detailed descriptions. Your job is to:

1. Evaluate first - Is the existing description good? Better than a template?
2. Preserve quality - Don't replace a thorough description with a generic template
3. Enhance, don't replace - Add missing required elements (NOTE block, issue links) without rewriting good content
4. Only rewrite if needed - When description is stale, inaccurate, or missing key information

Usage

# Get current state (no local checkout required)
gh pr view XXXXX --json title,body
gh pr view XXXXX --json files --jq '.files[].path'

# Review commit messages (helpful for squash/merge commit quality)
gh pr view XXXXX --json commits --jq '.commits[].messageHeadline'

# Review actual code changes
gh pr diff XXXXX

# Optional: if the PR branch is checked out locally
git diff origin/main...HEAD

Evaluation Workflow

Step 1: Review Existing Description Quality

Before suggesting changes, evaluate the current description:

Quality Indicator	Look For
Structure	Clear sections, headers, organized flow
Technical depth	File-by-file changes, specific code references
Scanability	Easy to find what changed and where
Accuracy	Matches actual diff - not stale or incorrect
Completeness	Platforms, breaking changes, testing info

Step 2: Compare to Template

Ask: "Is the existing description better than what my template would produce?"

• If YES: Keep existing, only add missing required elements
• If NO: Suggest improvements or replacement

Step 3: Produce Output

• Recommended PR title (if change needed)
• Assessment of existing description
• Specific additions needed (e.g., "Add NOTE block at top")
• Only full replacement if description is inadequate

Title Requirements

The title becomes the commit message headline. Make it searchable and informative.

Requirement	Good	Bad
Platform prefix (if specific)	[iOS] Fix Shell back button	Fix Shell back button
Describes behavior, not issue	[iOS] SafeArea: Return Empty for non-ISafeAreaView views	Fix #23892
Captures the "what"	Return Empty for non-ISafeAreaView	Fix SafeArea bug
Notes model change if applicable	(opt-in model)	(omitted)
No noise prefixes	[iOS] Fix...	[PR agent] Fix...

Title Formula

[Platform] Component: What changed (model change if any)

Examples:

• [iOS] SafeArea: Return Empty for non-ISafeAreaView views (opt-in model)
• [Android] CollectionView: Fix scroll position reset on item update
• [Windows] Shell: Use NavigationView instead of custom flyout

Description Requirements

PR description should:

1. Include the base sections from .github/PULL_REQUEST_TEMPLATE.md ("Description of Change" and "Issues Fixed"). The skill adds additional structured fields (Root cause, Fix, Key insight, etc.) as recommended enhancements for better agent context.
2. Match the actual implementation

### Description of Change
[Must match actual implementation]

### Issues Fixed
Fixes #XXXXX

Content for Future Agents

The title and description become the commit message. Future agents searching git history will use this to understand:

• What changed and why
• What patterns to follow or avoid
• How this change affects related code

Required Elements for Agent Success

Element	Purpose	Example
Root cause	Why the bug occurred	"Non-ISafeAreaView views falling through to return baseSafeArea"
Fix approach	What the code now does	"Return SafeAreaPadding.Empty for views without interface"
Philosophy/model change	If behavior model changed	"Before: opt-out. After: opt-in via interface"
Key interfaces/types	Types agents need to know	"ISafeAreaView, ISafeAreaView2 = opt-in contract"
What NOT to do	Failed approaches to avoid	"Don't use Element type in Platform layer"
Architectural constraints	Layer boundaries, type availability	"Platform layer cannot reference Controls types"
Edge cases	Known limitations or risks	"Legacy layouts are [Obsolete], custom views need interface"

"What NOT to Do" Section (Critical)

When try-fix or debugging revealed failed approaches, document them:

### What NOT to Do (for future agents)

- ❌ **Don't use [Type] in [Layer]** - [Why it fails]
- ❌ **Don't use [Pattern]** - [Why it's brittle/wrong]
- ❌ **Don't [Approach]** - [Why it doesn't work]

This prevents future agents from repeating failed experiments.

Philosophy/Model Changes

When a fix changes the behavioral model (not just fixing a bug), call it out explicitly:

**This is a philosophy change:**
- **Before:** [Old behavior model]
- **After:** [New behavior model]

Example: "Before: Safe area applied by default (opt-out). After: Only views implementing ISafeAreaView get safe area (opt-in)."

Common Issues

Problem	Cause	Solution
Description doesn't match code	Implementation changed during review	Update description to match actual diff
Missing root cause	Author focused on "what" not "why"	Add root cause from issue/analysis
References wrong approach	Started with A, switched to B	Update to describe final approach
Missing NOTE block	Author didn't use template	Prepend NOTE block, keep rest
Good description replaced	Agent used template blindly	Evaluate existing quality first

Output Format

When Existing Description is Good

## PR #XXXXX Finalization Review

### ✅ Title: [Good / Needs Update]
**Current:** "Existing title"
**Recommended:** "[Platform] Improved title" (if needed)

### ✅ Description: Excellent - Keep As-Is

**Quality assessment:**
- Structure: ✅ Clear sections with headers
- Technical depth: ✅ File-by-file breakdown
- Accuracy: ✅ Matches implementation
- Completeness: ✅ Platforms, breaking changes noted

**Only addition needed:**
- ❌ Missing NOTE block - prepend to top

**Action:** Add NOTE block, preserve everything else.

When Description Needs Rewrite

Use structured template only when existing description is inadequate:

### Root Cause

[Why the bug occurred - be specific about the code path]

### Description of Change

[What the code now does]

**This is a philosophy change:** (if applicable)
- **Before:** [Old model]
- **After:** [New model]

[Cross-platform alignment notes if relevant]

### Key Technical Details

**[Relevant interfaces/types]:**
- `InterfaceA` - [What it does]
- `InterfaceB` - [What it does]

**[Category] that [work/don't work]:**
- List of types/views affected

### What NOT to Do (for future agents)

- ❌ **Don't [approach 1]** - [Why it fails]
- ❌ **Don't [approach 2]** - [Why it's wrong]
- ❌ **Don't [approach 3]** - [Constraint that prevents it]

### Edge Cases

| Scenario | Risk | Mitigation |
|----------|------|------------|
| [Case 1] | Low/Medium/High | [How to handle] |
| [Case 2] | Low/Medium/High | [How to handle] |

### Issues Fixed

Fixes #XXXXX

### Platforms Tested

- [x] iOS
- [x] Android
- [ ] Windows
- [ ] Mac

Quality Comparison Examples

Good Existing Description (KEEP)

## Changes Made

### 1. **PickerHandler.iOS.cs** - MacCatalyst-specific improvements

#### Added UIAlertController instance field
- Declared `UIAlertController? pickerController` as instance field...

#### Improved picker dismiss logic
- Moved picker dismiss logic from event handler to "Done" button action
- Removed `EditingDidEnd` event handler causing duplicate dismiss calls

## Platforms Affected
- **MacCatalyst** (primary)
- iOS (no behavior changes, shared code)

## Breaking Changes
None

Verdict: Excellent - file-by-file breakdown, specific changes, platforms, breaking changes. Keep it.

Poor Existing Description (REWRITE)

Fixed the issue mentioned in #30897

Verdict: Inadequate - no detail on what changed. Use template.

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Phase 2: Code Review

After verifying title/description, perform a code review to catch best practice violations and potential issues before merge.

Review Focus Areas

When reviewing code changes, focus on:

1. Code quality and maintainability - Clean code, good naming, appropriate abstractions
2. Error handling and edge cases - Null checks, exception handling, boundary conditions
3. Performance implications - Unnecessary allocations, N+1 queries, blocking calls
4. Platform-specific concerns - iOS/Android/Windows differences, platform APIs
5. Breaking changes - API changes, behavior changes that affect existing code

How to Review

# Get the PR diff
gh pr diff XXXXX

# Review specific files
gh pr diff XXXXX -- path/to/file.cs

Output Format

## Code Review Findings

### 🔴 Critical Issues

**[Issue Title]**
- **File:** [path/to/file.cs]
- **Problem:** [Description]
- **Recommendation:** [Code fix or approach]

### 🟡 Suggestions

- [Suggestion 1]
- [Suggestion 2]

### ✅ Looks Good

- [Positive observation 1]
- [Positive observation 2]

🚨 CRITICAL: Do NOT Post Comments Directly

The pr-finalize skill is ANALYSIS ONLY. Never post comments using gh pr review or gh pr comment.

Action	Allowed?	Why
gh pr review --comment	❌ NEVER	Review-PR.ps1 handles posting via scripts
gh pr comment	❌ NEVER	Review-PR.ps1 handles posting via scripts
Analyze and report findings	✅ YES	This is the skill's purpose

Workflow:

1. This skill: Analyze PR, produce findings and write to pr-finalize-summary.md
2. Review-PR.ps1 calls post-pr-finalize-comment.ps1 to post the summary

The user controls when comments are posted. Your job is to analyze and present findings.

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Complete Example

See references/complete-example.md for a full agent-optimized PR description showing all elements above applied to a real SafeArea fix.