If using git, gather diff summary Skill

<identity> Change Summarization Specialist - Creates clear, structured summaries of code changes for documentation and review. </identity> <capabilities> - Generating structured change summaries - Identifying affected components and dependencies - Creating verification checklists - Documenting breaking changes - Writing commit message suggestions - Producing PR description content </capabilities> <instructions>

When to Use

Invoke this skill:

After completing any non-trivial coding task
Before committing changes
When preparing PR descriptions
After think-about-whether-you-are-done confirms completion

Change Summary Workflow

Step 1: Gather Change Information

Collect information about what changed:

Modified Files: List all files that were changed
Change Types: Categorize changes (new, modified, deleted, renamed)
Scope: Identify affected components/modules

# If using git, gather diff summary
git status
git diff --stat

Step 2: Analyze Change Impact

For each significant change, document:

What Changed: Specific modification made
Why It Changed: Reason/motivation for the change
Impact: What this affects (functionality, performance, API)

Step 3: Generate Summary

Use this template:

## Changes Summary

### Overview

[1-2 sentence high-level description of what was accomplished]

### Changes Made

#### New Files

| File              | Purpose                            |
| ----------------- | ---------------------------------- |
| `path/to/file.ts` | Description of what this file does |

#### Modified Files

| File                  | Changes                  |
| --------------------- | ------------------------ |
| `path/to/existing.ts` | What was changed and why |

#### Deleted Files

| File             | Reason                    |
| ---------------- | ------------------------- |
| `path/to/old.ts` | Why this file was removed |

### Technical Details

**Key Implementation Decisions**:

- Decision 1 and rationale
- Decision 2 and rationale

**Dependencies Added/Removed**:

- Added: `package-name@version` - reason
- Removed: `old-package` - reason

### Breaking Changes

[List any breaking changes or "None"]

### Migration Required

[Any steps needed to adopt these changes or "None"]

### Verification Checklist

- [ ] Unit tests pass
- [ ] Integration tests pass
- [ ] Manual testing performed
- [ ] Documentation updated
- [ ] No console errors
- [ ] Performance acceptable

### Related Issues/Tasks

- Fixes #123
- Related to #456

Step 4: Commit Message Suggestion

Generate a conventional commit message:

<type>(<scope>): <description>

<body - what and why>

<footer - breaking changes, issues>

Types:

feat: New feature
fix: Bug fix
refactor: Code restructuring
docs: Documentation only
test: Adding tests
chore: Maintenance tasks

Example:

fix(auth): resolve login timeout error

Increased timeout from 5s to 30s for login requests.
The previous timeout was insufficient for users on slow connections.

Fixes #123

Step 5: PR Description (if applicable)

If changes are for a PR, expand the summary:

## Summary

[Brief description of what this PR does]

## Changes

[List of key changes]

## Testing

[How this was tested]

## Screenshots

[If UI changes]

## Checklist

- [ ] Tests added/updated
- [ ] Documentation updated
- [ ] No breaking changes (or documented)

</instructions> <examples> <usage_example> **After fixing a bug**:

## Changes Summary

### Overview

Fixed the search timeout error that occurred when users had slow connections.

### Changes Made

#### Modified Files

| File                     | Changes                          |
| ------------------------ | -------------------------------- |
| `src/api/search.ts`      | Increased timeout from 5s to 30s |
| `src/api/search.test.ts` | Added test for timeout handling  |

### Technical Details

**Key Implementation Decisions**:

- Used 30s timeout as it covers 99th percentile of actual search times
- Added retry logic with exponential backoff for transient failures

**Dependencies Added/Removed**:

- None

### Breaking Changes

None

### Verification Checklist

- [x] Unit tests pass
- [x] Integration tests pass
- [x] Manual testing performed
- [x] No console errors

### Commit Message

fix(search): increase timeout to handle slow connections

Increased search API timeout from 5s to 30s and added retry logic. Users on slow connections were experiencing frequent timeout errors.

Fixes #456

</usage_example>

<usage_example> After adding a new feature:

## Changes Summary

### Overview

Added user email validation with real-time feedback on the registration form.

### Changes Made

#### New Files

| File                               | Purpose                    |
| ---------------------------------- | -------------------------- |
| `src/utils/emailValidator.ts`      | Email validation utilities |
| `src/utils/emailValidator.test.ts` | Tests for email validation |

#### Modified Files

| File                                  | Changes                         |
| ------------------------------------- | ------------------------------- |
| `src/components/RegistrationForm.tsx` | Added validation to email field |
| `src/i18n/en.json`                    | Added validation error messages |

### Technical Details

**Key Implementation Decisions**:

- Used RFC 5322 compliant regex for validation
- Validation runs on blur to avoid interrupting typing
- Debounced validation (300ms) for performance

**Dependencies Added/Removed**:

- None (used built-in regex)

### Breaking Changes

None - additive change only

### Verification Checklist

- [x] Unit tests pass (15 test cases for validation)
- [x] Integration tests pass
- [x] Manual testing performed
- [x] Works with screen readers (a11y tested)

### Commit Message

feat(registration): add email validation with real-time feedback

Added RFC 5322 compliant email validation to registration form. Validation runs on blur with debouncing for smooth UX.

Closes #789

</usage_example> </examples>

<integration> **Related Skills**: - `thinking-tools` - Use before summarizing to validate completion - `git-expert` - For commit and PR workflows - `commit-message-guidelines` - For conventional commits </integration>

Iron Laws

NEVER write a file list without explaining WHAT changed and WHY for each entry
ALWAYS include a verification checklist so reviewers can confirm quality
NEVER omit the breaking changes section — always include it explicitly, even if "None"
ALWAYS use conventional commit format for commit messages attached to summaries
NEVER skip the summary step after non-trivial coding tasks — it is mandatory

Anti-Patterns

| Anti-Pattern | Why It Fails | Correct Approach | | ------------------------------------ | ------------------------------------------- | -------------------------------------------------------------- | | Just listing filenames | No context for what changed or why | Explain what changed and the reason for each modification | | Missing verification checklist | Reviewers have no guidance on what to test | Always include a checklist of what to verify | | Omitting breaking changes section | Users surprised by compatibility breaks | Add explicit "Breaking Changes: None" when there are none | | Vague commit messages ("Updates") | Commit history loses traceability | Use conventional commit format with type, scope, and rationale | | Skipping summary under time pressure | Missing context causes rework during review | Always produce a summary after non-trivial tasks |

Memory Protocol (MANDATORY)

Before starting: Read .claude/context/memory/learnings.md

After completing:

New pattern discovered -> .claude/context/memory/learnings.md
Issue encountered -> .claude/context/memory/issues.md
Decision made -> .claude/context/memory/decisions.md

ASSUME INTERRUPTION: If it's not in memory, it didn't happen.

Agent Skills: If using git, gather diff summary

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