# Evidence First Planning

> Trigger: deep plan, evidence-first plan, planificar a fondo, planificacion basada en evidencia, discovery plan. Discover decisions and plan executable work from repository evidence.

- Skill: `andresnator/evidence-first-planning` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add andresnator/evidence-first-planning`
- Raw SKILL.md: https://api.skillmd.com/api/skills/andresnator/evidence-first-planning/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Product & Planning
- License: MIT
- Author: andresnator (https://skillmd.com/u/andresnator)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/andresnator/evidence-first-planning

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## Contract

Plan before implementation. Read relevant code and contracts; never edit production code, build, install, test, commit, or push. Planning artifacts are the only writes.

## Method

1. **Evidence first.** Verify implementations, callers, tests, tool versions, and reusable `path:symbol` elements. Cite `path:line` or mark `hypothesis`.
2. **Ask only decisions.** Explore repository facts. Ask each unresolved open-ended scope, product, acceptance, or risk choice directly in normal chat and wait. Add `Recommendation: ...` only when useful; reserve the `question` tool for closed choices.
3. **Validate edges.** Every edge is handled, out of scope, or an open question. Use `references/edge-validation.md`.
4. **Stay proportional.** Keep only information that changes execution; record meaningful rejected alternatives briefly.
5. **Prove the flow.** End with executable commands or an observable end-to-end check and its expected result.

## Wayfinder discovery

Use `assets/discovery-template.md`. Write one `.ai/deep-planner/discoveries/<slug>.md`. Do not add status, phase, or readiness markers. Keep evidence, decisions, and unresolved questions current. When the destination is clear, suggest converting the discovery into a plan.

## Deep Plan

Load `execution-plan` and write one `.ai/deep-planner/plans/<slug>.md`. Large efforts remain one plan with work groups and explicit dependencies. Do not create roadmaps, slices, readiness markers, or companion phase documents.

## Outputs

- Wayfinder: one discovery file and no plan.
- Deep Plan: one plan file and no discovery, roadmap, or change file.

Before returning, check evidence, edges, proportionality, exact paths, and end-to-end verification. Report only the artifact path and next route.

## Resources

- `assets/discovery-template.md`
- `references/edge-validation.md`
- `references/question-economy.md`