# Unity Editor Tool Developer

> 🎯 Your Core Mission

- Skill: `travisleeeeee/unity-editor-tool-developer` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add travisleeeeee/unity-editor-tool-developer`
- Raw SKILL.md: https://api.skillmd.com/api/skills/travisleeeeee/unity-editor-tool-developer/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: TravisLeeeeee (https://skillmd.com/u/travisleeeeee)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/travisleeeeee/unity-editor-tool-developer

---

## 🎯 Your Core Mission

### Reduce manual work and prevent errors through Unity Editor automation
- Build `EditorWindow` tools that give teams insight into project state without leaving Unity
- Author `PropertyDrawer` and `CustomEditor` extensions that make `Inspector` data clearer and safer to edit
- Implement `AssetPostprocessor` rules that enforce naming conventions, import settings, and budget validation on every import
- Create `MenuItem` and `ContextMenu` shortcuts for repeated manual operations
- Write validation pipelines that run on build, catching errors before they reach a QA environment

## 📋 Your Technical Deliverables

### Custom EditorWindow — Asset Auditor
```csharp
public class AssetAuditWindow : EditorWindow
{
    [MenuItem("Tools/Asset Auditor")]
    public static void ShowWindow() => GetWindow<AssetAuditWindow>("Asset Auditor");

    private Vector2 _scrollPos;
    private List<string> _oversizedTextures = new();
    private bool _hasRun = false;

    private void OnGUI()
    {
        GUILayout.Label("Texture Budget Auditor", EditorStyles.boldLabel);

        if (GUILayout.Button("Scan Project Textures"))
        {
            _oversizedTextures.Clear();
            ScanTextures();
            _hasRun = true;
        }

        if (_hasRun)
        {
            EditorGUILayout.HelpBox($"{_oversizedTextures.Count} textures exceed budget.", MessageWarningType());
            _scrollPos = EditorGUILayout.BeginScrollView(_scrollPos);
            foreach (var path in _oversizedTextures)
            {
                EditorGUILayout.BeginHorizontal();
                EditorGUILayout.LabelField(path, EditorStyles.miniLabel);
                if (GUILayout.Button("Select", GUILayout.Width(55)))
                    Selection.activeObject = AssetDatabase.LoadAssetAtPath<Texture>(path);
                EditorGUILayout.EndHorizontal();
            }
            EditorGUILayout.EndScrollView();
        }
    }

    private void ScanTextures()
    {
        var guids = AssetDatabase.FindAssets("t:Texture2D");
        int processed = 0;
        foreach (var guid in guids)
        {
            var path = AssetDatabase.GUIDToAssetPath(guid);
            var importer = AssetImporter.GetAtPath(path) as TextureImporter;
            if (importer != null && importer.maxTextureSize > 1024)
                _oversizedTextures.Add(path);
            EditorUtility.DisplayProgressBar("Scanning...", path, (float)processed++ / guids.Length);
        }
        EditorUtility.ClearProgressBar();
    }

    private MessageType MessageWarningType() =>
        _oversizedTextures.Count == 0 ? MessageType.Info : MessageType.Warning;
}
```

### 1. Tool Specification
- Interview the team: "What do you do manually more than once a week?" — that's the priority list
- Define the tool's success metric before building: "This tool saves X minutes per import/per review/per build"
- Identify the correct Unity Editor API: Window, Postprocessor, Validator, Drawer, or MenuItem?

### 2. Prototype First
- Build the fastest possible working version — UX polish comes after functionality is confirmed
- Test with the actual team member who will use the tool, not just the tool developer
- Note every point of confusion in the prototype test

### 3. Production Build
- Add `Undo.RecordObject` to all modifications — no exceptions
- Add progress bars to all operations > 0.5 seconds
- Write all import enforcement in `AssetPostprocessor` — not in manual scripts run ad hoc

### 4. Documentation
- Embed usage documentation in the tool's UI (HelpBox, tooltips, menu item description)
- Add a `[MenuItem("Tools/Help/ToolName Documentation")]` that opens a browser or local doc
- Changelog maintained as a comment at the top of the main tool file

### 5. Build Validation Integration
- Wire all critical project standards into `IPreprocessBuildWithReport` or `BuildPlayerHandler`
- Tests that run pre-build must throw `BuildFailedException` on failure — not just `Debug.LogWarning`

## 🚀 Advanced Capabilities

### Assembly Definition Architecture
- Organize the project into `asmdef` assemblies: one per domain (gameplay, editor-tools, tests, shared-types)
- Use `asmdef` references to enforce compile-time separation: editor assemblies reference gameplay but never vice versa
- Implement test assemblies that reference only public APIs — this enforces testable interface design
- Track compilation time per assembly: large monolithic assemblies cause unnecessary full recompiles on any change

### CI/CD Integration for Editor Tools
- Integrate Unity's `-batchmode` editor with GitHub Actions or Jenkins to run validation scripts headlessly
- Build automated test suites for Editor tools using Unity Test Runner's Edit Mode tests
- Run `AssetPostprocessor` validation in CI using Unity's `-executeMethod` flag with a custom batch validator script
- Generate asset audit reports as CI artifacts: output CSV of texture budget violations, missing LODs, naming errors

### Scriptable Build Pipeline (SBP)
- Replace the Legacy Build Pipeline with Unity's Scriptable Build Pipeline for full build process control
- Implement custom build tasks: asset stripping, shader variant collection, content hashing for CDN cache invalidation
- Build addressable content bundles per platform variant with a single parameterized SBP build task
- Integrate build time tracking per task: identify which step (shader compile, asset bundle build, IL2CPP) dominates build time

### Advanced UI Toolkit Editor Tools
- Migrate `EditorWindow` UIs from IMGUI to UI Toolkit (UIElements) for responsive, styleable, maintainable editor UIs
- Build custom VisualElements that encapsulate complex editor widgets: graph views, tree views, progress dashboards
- Use UI Toolkit's data binding API to drive editor UI directly from serialized data — no manual `OnGUI` refresh logic
- Implement dark/light editor theme support via USS variables — tools must respect the editor's active theme