how ยท diff
git:20260923.11fd787 to git:20261014.8882c71
12 added, 29 removed. Audit A to A.
---
name: how
description: "Use for \"how does X work\", code walkthroughs before changing something, and placement / ownership / layering questions (\"where should this live\", \"which package owns this\", \"is this the right layer\"). Explains subsystem architecture, runtime flow, onboarding mental models. Use why for motivation."
disable-model-invocation: true
---
# How
Explore the codebase to answer "how does X work?" questions. Produce architectural explanations at the level of a senior engineer onboarding onto a subsystem, enough to build a working mental model, not so much that it reads like annotated source code.
- ## Step 1. Assess Complexity
+ Every spawn uses the Agent tool with `subagent_type: "pstack:read-only"`. Explorers run on the `how explorer` model and every explainer on the `how explainer` model, both from `${CLAUDE_SKILL_DIR}/../poteto-mode/references/models.md`.
+ ## 1. Assess complexity
+
If the scope is ambiguous, state your interpretation and explore. The user can redirect.
- - **Simple** (a single module, a small utility, a narrow question such as "how does function X work"): no explorers. One explainer explores and explains in a single pass. Go to Step 2b.
- - **Complex** (a subsystem spanning multiple files or services, a cross-cutting feature, a full architectural overview): spawn parallel explorers first, then hand off to the explainer. Go to Step 2a.
+ - **Simple** (a single module, a small utility, a narrow question such as "how does function X work"): no explorers. Spawn one explainer that explores and explains in one pass, built from `${CLAUDE_SKILL_DIR}/references/explainer-prompt.md` without the explorer-findings section. Go to step 4.
+ - **Complex** (a subsystem spanning multiple files or services, a cross-cutting feature, a full architectural overview): go to step 2.
When in doubt, take the simple path.
- ## Step 2a. Explore (complex questions only)
-
- Decompose the question into 2 to 4 exploration angles, each a distinct slice of the subsystem. Spawn all explorers with the Agent tool in a single message:
-
- - `subagent_type`: `pstack:read-only`
- - `model`: the `how explorer` model from `${CLAUDE_SKILL_DIR}/../poteto-mode/references/models.md`
-
- Each explorer gets the prompt in `${CLAUDE_SKILL_DIR}/references/explorer-prompt.md` with its angle filled in. Then go to Step 3.
-
- ## Step 2b. Direct Explain (simple questions)
-
- Spawn one subagent that explores and explains in one pass:
-
- - `subagent_type`: `pstack:read-only`
- - `model`: the `how explainer` model from `models.md`
-
- Build its prompt from `${CLAUDE_SKILL_DIR}/references/explainer-prompt.md` without the explorer-findings section. Go to Step 4.
-
- ## Step 3. Synthesize (complex questions only)
+ ## 2. Explore (complex only)
- Once all explorers have returned, spawn one subagent to synthesize their findings into one explanation:
+ Decompose the question into 2 to 4 angles, each a distinct slice of the subsystem. Spawn all explorers in a single message, each with `${CLAUDE_SKILL_DIR}/references/explorer-prompt.md` and its angle filled in.
- - `subagent_type`: `pstack:read-only`
- - `model`: the `how explainer` model from `models.md`
+ ## 3. Synthesize (complex only)
- Build its prompt from `${CLAUDE_SKILL_DIR}/references/explainer-prompt.md` with every explorer's findings filled in.
+ Once all explorers have returned, spawn one explainer with `${CLAUDE_SKILL_DIR}/references/explainer-prompt.md` and every explorer's findings filled in.
- ## Step 4. Present
+ ## 4. Present
- Present the explainer's output to the user. Light edits for clarity or context from the conversation are fine. Do not substantially rewrite it.
+ Present the explainer's output. Light edits for clarity or context from the conversation are fine. Do not substantially rewrite it.
- ## Output Format
+ ## Output format
The explanation uses the sections defined in `${CLAUDE_SKILL_DIR}/references/explainer-prompt.md`, dropping any that do not apply: Overview, Key Concepts, How It Works, Where Things Live, Gotchas.