How

Answer "how does X work?" with the mental model a senior would give on day one. Not annotated source.

/why answers why it is this way. /analyze writes the broader memo (a bug, an idea, impact, an execution seed). This skill does not write tickets or code, and it does not start a build. The selected execution skill owns any later build.

The section shape is adapted from poteto's pstack /how (MIT). The steps below are this pack's.

Read when

• About to search the repo or read large files? Open main-context.md. Skip it and the walkthrough drowns in file dumps.
• About to describe layers, ownership, or a public API? Open code-quality.md and code-structure.md. Skip them and the model copies a messy layout.
• About to reply? Open Plain language and Unslop. Skip them and the walkthrough reads like a tour script.
• About to ask the user anything? Open Asking the user. Skip it and you ask what the repo already answers.

Contract

• Read only. Do not edit code, open a ticket, or start /task.
• Judgment stays in this chat. Bulk reading goes to readonly explorers that return a short result.
• Use the shared roles and selection policy: explorers gather evidence; analyzers synthesize only as deeply as the actual uncertainty requires. Routine lookups do not require a strong reasoning model.

Process

1. Name the thing: a flow, a module, or a request path. If two targets fit, ask once which one, with a recommendation.
2. Judge simple or complex before reading widely.
   • Simple: one cohesive path, a few files, one owner. One readonly pass in this chat, with narrow reads. No explorer.
   • Complex: several layers, several owners, or a path you cannot hold in one pass. Launch 2 to 4 readonly explorers in parallel. Ask each for paths, symbols, and a short note. Synthesize here. When the harness has no subagent, do the same pass as narrow reads, one area at a time, then synthesize once.
3. Standalone, write the sections below. Lead with the model. Do not paste source as the answer. Nested, follow nested capabilities: return only the requested flow, owners, source pointers, and uncertainty. Give explorers the parent's locked outcome, bounded question, existing evidence, and stopping condition; reuse existing scouts instead of duplicating the investigation. The parent owns design synthesis.

Answer

Overview

What it does, who calls it, and what it returns or changes. A few sentences.

Key concepts

The few nouns a newcomer must have. One sentence each.

How it works

The path, in order. Name the modules. A small Mermaid diagram when the path has more than two hops.

Where things live

Paths and the job of each. Who owns the public API, and what callers must not import.

Gotchas

Traps that are real in this code: ordering, a caller that defeats a rule, a name that lies. If there are none, say there are none.

Anti-patterns

• Annotated source in place of the model
• A second build loop
• Inventing a layer the code does not have
• Launching explorers for a one-file path
• Writing a ticket or editing code