Agent Skills: Brainstorm a Feature or Improvement

Brainstorm a Feature or Improvement

Brainstorming answers WHAT to build through dialogue; ce-plan then enriches the same unified plan artifact with HOW. This skill does not implement code. The current year is 2026, for dating the artifact.

Outcome: a right-sized result planning can enrich without inventing product behavior, scope boundaries, or success criteria: a chat paragraph for Lightweight work, or a requirements-only unified plan under <root>/plans/ when a file is earned.

Done, on the brainstorm path: that artifact is written and passes the Ready for Planning Check — or no file was written because the dialogue produced no decision a downstream consumer needs in IDed form and the user asked for none — and Phase 4's handoff has been presented.

Lightweight work ends in chat. Phase 0.3 classifies the tier from the request and bounded inline reads before anything is dispatched; when the tier is uncertain, take the heavier one. Lightweight work — small, well-bounded, low ambiguity — ends in a chat paragraph with no file, no grounding scout, no approach generation, and no claim verifier. A file is earned only by a decision a downstream consumer needs in IDed form, or by the user asking for one.

Stop and route instead in three cases, decided by references/phase-0.md, not from memory. Each ends the run its own way, so the done bar above does not apply: non-software work, where references/universal-brainstorming.md replaces Phases 0.2–4; a verdict question about a named external candidate, where you offer the ce-pov handoff; and neither — quick help, a factual question, a single-step task — answered directly.

The feature description is what the invocation carries, whether the user wrote it or a calling skill passed it. If none came, ask the user what they want to explore and do not proceed until you have one.

Artifact Root

Resolve <root> the first time you compose or read a <root>/ path, never earlier; a scratch-only or no-repo run that touches none skips this entirely.

Resolve the CE artifact root <root> before composing any artifact path.

• Read docs_root from <repo-root>/.compound-engineering/config.yaml only (<repo-root> = git rev-parse --show-toplevel). Do not read it from config.local.yaml. Unset -> <root> is docs, exactly as before.
• Validate a set value: a repo-relative directory whose real, symlink-resolved path stays inside the repo and is neither the repo root nor under .git/. Otherwise stop with an error naming docs_root and the value -- never fall back to docs.
• Use <root> as the sole artifact location: create it if absent, compose each path as <root>/<subdir> with this skill's own subdirectory, and never also read docs.

brainstorm_output and brainstorm_model resolve by this rule instead:

Resolve ordinary CE yaml keys from the two repo files.

• Read <repo-root>/.compound-engineering/config.local.yaml, then config.yaml (<repo-root> = git rev-parse --show-toplevel). Missing files are skipped. Gitignore does not change resolution.
• Win with the first active (non-commented) value. For scalars, empty is unset; an invalid value continues to the next layer, then the skill default. For lists and maps, a present key — including an empty list or map — replaces the whole key.
• Do not use this rule for docs_root — that key is config.yaml only.

Execution Flow

Phases run in this order. Each names the files it cannot run correctly without: read them when you reach it, and never do its work from this table alone.

| Phase | Read first | What only those files carry | |---|---|---| | before the first question, and for the whole run — non-software route included | Read references/interaction-rules.md | the Core Principles, and the Interaction Rules: one question per turn, ask only decisions the environment cannot settle, the blocking-question-tool default and the visual-probe gate that overrides it, when a question is genuinely open-ended, and the one ce-prototype routing test this skill states in full there | | before treating a decision the conversation carries as settled | Read references/settled-decisions.md | the settlement test; skipping it re-asks a decided question or promotes an unexamined assertion | | 0.0 output mode | references/output-mode.md | the OUTPUT_FORMAT precedence; the token-parsing convention | | 0.1–0.4 resume, classify, route, scope | references/phase-0.md | resume scan; the stop-and-route classification; scope tiers; coherent-work gate; both tripwires; task spine | | 1 understand the idea | references/dialogue.md | context scan and grounding scout; opt-in Slack researcher; pressure test; blindspot and visual-probe gates; the conflict gate against existing CONCEPTS.md and verified code; Phase 1.3 exit condition | | 2–2.6 approaches, synthesis, verification | references/approaches.md, plus references/synthesis-summary.md before composing the synthesis | approach generation; model elevation; the scoping synthesis; the claim verifier | | 3 write the plan | references/plan-write.md, then references/brainstorm-sections.md and the rendering reference for the format | whether a doc is warranted; the section contract; the Ready for Planning Check | | 4 handoff | references/handoff.md | the option set and its visibility conditions; the rendering-mode rule; per-selection dispatch, including what ce-plan is passed; closing summaries |

These rules hold without any read:

OUTPUT_FORMAT is exclusive — markdown OR HTML, never both — and pipeline mode (LFG, or any disable-model-invocation context) forces md.

When a file is written on the brainstorm path the artifact contract does not change: write to <root>/plans/YYYY-MM-DD-HHMM-<type>-<topic>-plan.<md|html>, with HHMM from local wall-clock time at write; frontmatter carries artifact_contract: ce-unified-plan/v1, artifact_readiness: requirements-only, and product_contract_source: ce-brainstorm; the body is a Goal Capsule plus the Product Contract. Do not emit a Goal Launch Block or Reader Index. The non-software route writes none of this.

When a file is written, do not declare it written or enter Phase 4 while any check fails in the Ready for Planning Check; a chat result enters Phase 4 with no check to run. An improvised Phase 4 menu is the other silent failure: it surfaces options that must be hidden and passes the wrong payload downstream.

The Phase 1.1 grounding scout, the Phase 2.6 claim verifier, and the opt-in Slack researcher are tiered by task shape, never hardcoded to a model name; read references/model-tiers.md before dispatching one. Model elevation is a separate mechanism (references/reasoning-elevation.md).