Software implementation planning with file-based persistence (task_plan.md, findings.md, progress.md). Use when asked to "plan", "break down this feature", "implementation plan", or starting complex tasks needing >5 tool calls. Apply proactively before non-trivial coding.
Install
npx skillscat add iliaal/ai-skills/planning Install via the SkillsCat registry.
Planning
Core Principle
Context window = RAM (volatile, limited)
Filesystem = Disk (persistent, unlimited)
→ Anything important gets written to disk.Planning tokens are cheaper than implementation tokens. Front-load thinking; scale effort to complexity.
When to Plan
- Always plan: multi-file changes, new features, refactors, >5 tool calls
- Skip planning: single-file edits, quick lookups, simple questions
Planning Files
Create in project root before starting work:
| File | Purpose | Update When |
|---|---|---|
task_plan.md |
Phases, tasks, decisions, errors | After each phase |
findings.md |
Research, discoveries, code analysis | After any discovery |
progress.md |
Session log, test results, files changed | Throughout session |
Plan Template
# Plan: [Feature/Task Name]
## Approach
[1-3 sentences: what and why]
## Scope
- **In**: [what's included]
- **Out**: [what's explicitly excluded]
## Phase 1: [Name]
**Files**: [specific files, max 5-8 per phase]
**Tasks**:
- [ ] [Verb-first atomic task] — `path/to/file.ts`
- [ ] [Next task]
**Verify**: [specific test: "POST /api/users → 201", not "test feature"]
**Exit**: [clear done definition]
## Phase 2: [Name]
...
## Open Questions
- [Max 3, only truly blocking unknowns]Phase Sizing Rules
Every phase must be context-safe:
- Max 5-8 files touched
- Max 2 dependencies on other phases
- Fits in one 2-4 hour session (implementation + verification + fixes)
- If a phase violates these → split it
Clarifying Questions
Scale to complexity:
- Small task: 0-1 questions, assume reasonable defaults
- Medium feature: 1-2 questions on critical unknowns
- Large project: 3-5 questions (auth, data model, integrations, scope)
Only ask if truly blocking. Make reasonable assumptions for everything else.
Task Rules
- Atomic: one logical unit of work per task
- Verb-first: "Add...", "Create...", "Refactor...", "Verify..."
- Concrete: name specific files, endpoints, components
- Ordered: respect dependencies, sequential when needed
- Verifiable: include at least one validation task per phase
Context Management Rules
| Situation | Action |
|---|---|
| Starting new phase | Read task_plan.md (refresh goals in attention window) |
| After any discovery | Write to findings.md immediately |
| After completing phase | Update task_plan.md status, log to progress.md |
| After viewing image/PDF | Write findings NOW (multimodal content doesn't persist) |
| Resuming after gap | Read all planning files |
| Just wrote a file | Don't re-read it (still in context) |
| Error occurred | Log to task_plan.md, read relevant files for state |
Error Protocol
ATTEMPT 1: Diagnose root cause → targeted fix
ATTEMPT 2: Different approach (different tool, library, method)
ATTEMPT 3: Question assumptions → search for solutions → update plan
AFTER 3 FAILURES: Escalate to user with what you triedNever repeat the exact same failing action. Track attempts, mutate approach.
Iterative Refinement
For complex projects, iterate on the plan before implementing:
- Draft initial plan
- Review for gaps, missing edge cases, architectural issues
- Revise until suggestions become incremental
- Only then start implementation
5-Question Context Check
If you can answer these, your planning is solid:
| Question | Source |
|---|---|
| Where am I? | Current phase in task_plan.md |
| Where am I going? | Remaining phases |
| What's the goal? | Approach section |
| What have I learned? | findings.md |
| What have I done? | progress.md |
Anti-Patterns
| Don't | Do Instead |
|---|---|
| Start coding without a plan | Create task_plan.md first |
| State goals once and forget | Re-read plan before decisions |
| Hide errors and retry silently | Log errors, mutate approach |
| Keep everything in context | Write large content to files |
| Repeat failed actions | Track attempts in plan file |
| Create vague tasks ("improve X") | Concrete verb-first tasks with file paths |
| Plan phases with 12+ files | Split into 5-8 file chunks |
| Plan at 100% capacity | Budget for verification, fixes, and unknowns |