Assess

Use this skill after add-subfeature when an existing canonical feature has a selected durable subfeature and you need explicit impact assessment before subfeature-local design begins.

Read these references when relevant:

• references/config-surface-governance.md when the subfeature touches configuration, startup, compatibility boundaries, environment injection, or test harness inputs

Responsibilities

1. Resolve the target parent feature and selected subfeature.
2. Inspect parent planning artifacts under docs/features/<feature-slug>/.
3. Identify affected baseline artifacts, story IDs, planned slice IDs, and increment IDs.
4. Capture inherited constraints, especially existing ownership of configuration and state surfaces that the subfeature should reuse.
5. Write impact-analysis.md inside the selected subfeature folder.
6. Synchronize the discovered impact lists back into .subfeature-meta.json.

Preferred Input

• a parent feature slug, folder name, or path
• a subfeature ID, folder name, or path inside that feature's subfeatures/ registry
• optional explicit artifact, story, or slice IDs when the automatic baseline scan needs manual additions

Required Output

• <subfeature_path>/impact-analysis.md
• updated <subfeature_path>/.subfeature-meta.json

Workflow

1. Resolve the active subfeature created by add-subfeature.
2. Inspect parent feature docs such as discover.md, system-design.md, user-stories.md, slice-planning.md, and slice-traceability.md.
3. When the subfeature touches configuration or startup behavior, identify existing typed carriers, compatibility boundaries, and parent-owned control surfaces before design starts.
4. Write impact-analysis.md with baseline files reviewed, candidate affected stories, increments, slices, inherited constraints, and impact notes.
5. Persist the discovered artifact, story, and slice lists into the subfeature metadata.
6. Advance the subfeature to impact_ready when the artifact is complete.

Tooling

# Analyze one subfeature and advance it to impact_ready
python3 skills/assess/scripts/analyze_impact.py "checkout" "replace-legacy-flow"

# Add manual impact hints when needed
python3 skills/assess/scripts/analyze_impact.py \
  "checkout" "replace-legacy-flow" \
  --story-id "CHK-299" \
  --slice-id "CHK-902" \
  --affected-artifact "docs/features/checkout/user-stories.md"

Guardrails

• Do not use this skill for net-new canonical features; use discover for those.
• Do not treat impact analysis as execution-slice planning.
• Do not overwrite an existing impact-analysis.md unless the user is deliberately regenerating it.
• Keep the analysis tied to the selected subfeature, not the parent feature root.
• Do not let subfeature-local planning silently add a second control plane when the parent feature already owns the value through typed state or configuration.