fable-validate-fableplan git:20261006.4c6da76A

Immutable. This exact content never changes and is served at /api/v1/blob/314b2116eb5b43f1.

---
name: fable-validate-fableplan
description: >-
  Use when the user asks to validate a GitHub issue with Fable 5.1 and always plan it with Fable 5.1, stopping once the plan is posted — "fable-validate-fableplan", "fable validate and fable plan #N", "validate and plan #N with fable, don't build it". Runs fable-validate, auto-applies its update-issue edits when the verdict calls for it, then has fableplan produce and post a Fable 5.1 implementation plan for EVERY issue (no score gate), and stops at the posted plan — no worktree, no build, no PR, no review loop. Stops earlier when validation flags the issue as too large, architecturally infeasible, or already addressed by an existing PR. The no-implementation counterpart to fable-validate-fableplan-loop.
---

# fable-validate-fableplan

Chain fable-validate → (conditional) update issue → fableplan into one autonomous run, and stop there. The vetted plan is posted to the issue as a comment. **Nothing is built.**

This is **fable-validate-fableplan-loop with the handoff to `work-on-issue-loop` dropped**. When the plan should be built and driven through review in the same run, use `fable-validate-fableplan-loop`.

**Do not skip or reorder the chain.** Validation gates planning. There is no sanctioned skip: every step runs, and only the "wait for the user's reply" moments are replaced by the decision rules in the cited steps.

## Input

Same as fable-validate-loop, including the optional `targetBranch`.

## Steps

Follow **fable-validate-loop steps 1 through 4** with the changes below, then run this skill's step 5 in place of fable-validate-loop's steps 5 and 6:

**Step 1 (fable-validate):** also keep the verdict block and the validation report in the scratchpad; step 4 passes them to the planner.

**Step 2 (scope gate):** fable-validate-loop step 2's STOP table applies unchanged. An incomplete validation is never approval to plan.

**Step 3 (update-issue edits):** apply them per fable-validate step 5 / validate-issue step 11; the stacked `Validated with LLM: …` attribution line uses the harness suffix `fable-validate-fableplan`.

**Step 4 (fableplan):** there is **no score gate** — fable-validate-loop's score gate, safety carve-out, and top-band note do not apply; fableplan runs for every issue that passed the scope gate, whatever the validated score. Hand the planner the verdict block and validation report from step 1; the plan must respect what validation established (verified/refuted claims, the Optimal-direction note when architecture was Underspecified, 5c concerns). Instruct fableplan to use the harness suffix `fable-validate-fableplan` in the posted comment's attribution footer. fableplan stops at the posted plan, and so does this skill.

### 5. Report

Report, in order: scope gate passed, issue updated or not, plan posted (comment URL), and one line on what the plan proposes. Then name the follow-on options in one line — `work-on-issue` to build the plan and stop at the PR, `work-on-issue-loop` to build it and drive review to convergence, or `fable-validate-fableplan-loop` for the same chain end-to-end next time. **Do not start any of them.**

**Cap the whole report at 55 words and 5 sentences, plain simple English in ASD-STE100** — apply the Response Style rules in CLAUDE.md/AGENTS.md, written for a reader with no context on this codebase.

## Red Flags — STOP

fable-validate-loop's Red Flags rows for the scope gate, the step 2 human-decision rows (a) to (c), waiting on prompts, the bare issue number, the update-before-plan order, and a structurally wrong plan apply, with one substitution: in the structurally-wrong-plan row, read "post a broken plan" for "hand a broken plan to work-on-issue-loop". In addition:

| Situation | Action |
|---|---|
| Tempted to implement the plan, open a worktree, or open a PR | Stop at the posted plan; name `work-on-issue` / `work-on-issue-loop` / `fable-validate-fableplan-loop` as the follow-on instead of starting one |
| Tempted to skip validation and go straight to planning | Never reorder; there is no sanctioned skip |