GuillemRoca Using Agent Skills (Android)
Overview
This is the meta-skill — it defines how agents should work, not what they should build. Five core operating behaviors ensure agents produce reliable, high-quality Android code that matches project conventions and user intent.
Five Core Operating Behaviors
1. Surface Assumptions Explicitly
Before implementing non-trivial work, state your assumptions:
- "I'm assuming we're using MVVM, not MVI, for this screen"
- "I'm assuming minSdk 26 since that's in build.gradle.kts"
- "I'm assuming offline-first since the project uses Room as source of truth"
Why: Unstated assumptions are the #1 cause of wasted agent work. A wrong assumption in step 1 makes steps 2–10 wrong.
2. Manage Confusion
When encountering inconsistencies, stop and clarify:
- "The spec says use DataStore but the existing code uses SharedPreferences — which should I follow?"
- "TaskRepository has two different patterns — which is the intended one?"
- Name the specific confusion. Don't proceed with a guess.
3. Push Back When Warranted
Don't default to agreement. When a request has concrete downsides, say so:
- "Adding that dependency would increase APK size by ~2MB for a feature used by <1% of users"
- "Skipping tests here is risky because this ViewModel handles payment state"
- Provide the tradeoff, let the human decide.
4. Enforce Simplicity
Before writing code, ask: "Can this be done with less?"
- Resist unnecessary abstractions
- Don't add features beyond what's requested
- Three similar lines of code is better than a premature abstraction
- Follow project conventions, don't introduce new patterns
5. Maintain Scope Discipline
Only modify what's requested:
- Don't refactor neighboring code "while you're here"
- Don't add error handling for impossible scenarios
- Don't add comments to code you didn't change
- Don't upgrade dependencies unrelated to the task
Skill Discovery Flowchart
Match your current task to the right skill:
What are you trying to do?
│
├─ "I have a vague idea"
│ └─ idea-refine → spec-driven-development
│
├─ "I need to write a spec"
│ └─ spec-driven-development
│
├─ "I need to plan implementation"
│ └─ planning-and-task-breakdown
│
├─ "I need to build a feature"
│ ├─ Architecture decisions? → android-architecture
│ ├─ UI with Compose? → android-ui-engineering
│ ├─ Data persistence? → android-data-persistence
│ ├─ API/interface design? → api-and-interface-design
│ └─ General implementation → incremental-implementation + test-driven-development
│
├─ "I need to test"
│ ├─ Unit/integration tests → test-driven-development
│ ├─ Device/UI tests → android-device-testing
│ └─ Accessibility testing → android-accessibility
│
├─ "I need to review code"
│ ├─ Code quality → code-review-and-quality
│ ├─ Security review → security-and-hardening
│ └─ Performance review → performance-optimization
│
├─ "I need to debug"
│ └─ debugging-and-error-recovery
│
├─ "I need to simplify code"
│ └─ code-simplification
│
├─ "I need to ship"
│ ├─ CI/CD setup → ci-cd-and-automation
│ ├─ Version/release → git-workflow-and-versioning
│ └─ Launch checklist → shipping-and-launch
│
├─ "I need to migrate/deprecate"
│ └─ deprecation-and-migration
│
├─ "I need to write docs"
│ └─ documentation-and-adrs
│
├─ "I need to set up context for AI"
│ └─ context-engineering
│
├─ "I need to check official docs"
│ └─ source-driven-development
│
└─ "I'm not sure"
└─ Start with idea-refine or context-engineering
Quick Reference: All 24 Skills
| Phase | Skill | Trigger |
|---|---|---|
| DEFINE | idea-refine |
Vague idea needs sharpening |
| DEFINE | spec-driven-development |
Need a spec before coding |
| DEFINE | context-engineering |
Setting up AI context for project |
| PLAN | planning-and-task-breakdown |
Breaking work into tasks |
| PLAN | android-architecture |
Architecture decisions |
| BUILD | incremental-implementation |
Building feature step by step |
| BUILD | test-driven-development |
Writing tests before code |
| BUILD | android-ui-engineering |
Building Compose UI |
| BUILD | android-data-persistence |
Room, DataStore, offline-first |
| BUILD | api-and-interface-design |
Designing interfaces and contracts |
| BUILD | source-driven-development |
Using official docs for framework code |
| BUILD | code-simplification |
Making code easier to understand |
| BUILD | documentation-and-adrs |
Writing docs and ADRs |
| VERIFY | android-device-testing |
Instrumented tests, emulator, ADB |
| VERIFY | android-accessibility |
Accessibility compliance |
| VERIFY | debugging-and-error-recovery |
Fixing bugs systematically |
| VERIFY | performance-optimization |
Measuring and improving performance |
| REVIEW | code-review-and-quality |
Reviewing code quality |
| REVIEW | security-and-hardening |
Security review and hardening |
| SHIP | ci-cd-and-automation |
CI/CD pipeline setup |
| SHIP | git-workflow-and-versioning |
Git workflow and versioning |
| SHIP | shipping-and-launch |
Release checklist and rollout |
| SHIP | deprecation-and-migration |
Deprecating and migrating code |
| META | using-agent-skills |
How agents should operate |
Skills Are Workflows, Not Suggestions
- Follow steps in order — each step depends on the previous
- Never skip verification — "it looks right" is not evidence
- Produce tangible artifacts — specs, task lists, test results, not just prose
- Anti-rationalizations are real — if you're about to skip a step, check the "Common Rationalizations" table
- Assumption-making without validation is the most common failure mode
Verification
- Assumptions stated explicitly before implementation
- Confusion surfaced (not silently resolved with guesses)
- Pushback provided when warranted (with tradeoffs)
- Simplicity enforced (no unnecessary abstractions)
- Scope maintained (only requested changes made)
- Correct skill loaded for the current task