ctx-explain

name	ctx-explain
description	Explain code for someone new to the project. Use when the user asks 'what does this do', 'explain this', or wants to understand unfamiliar code.
allowed-tools	Read, Grep, Glob

Explain the specified code for someone new to the project. Tailor depth to the user's expertise if known from context.

When to Use

• User says "explain this code", "explain this", "what does this do"
• User is onboarding to an unfamiliar area of the codebase
• User says "walk me through this" or "how does this work"

When NOT to Use

• User wants deep architectural analysis (use /ctx-architecture)
• User wants to trace a bug — if you have an external debugging-aware skill (the GitNexus suite ships /gitnexus-debugging), invoke it; otherwise proceed with built-in reasoning
• User wants execution flow tracing — if you have an external flow-tracing skill (the GitNexus suite ships /gitnexus-exploring), invoke it; otherwise reason from the source

Explanation Structure

Cover each dimension in order. Skip any that don't apply.

1. What it does: Describe the purpose and behavior in plain language.
2. Why it exists: What problem does it solve? What would break without it?
3. How it connects: Which modules call it, and which modules does it depend on?
4. Key design decisions: Why was this approach chosen over alternatives?
5. Non-obvious details: Anything surprising, subtle, or easy to misunderstand.

Execution

1. Read the target code
2. Read .context/ARCHITECTURE.md for system-level context
3. Trace callers and callees if connections matter
4. Present the explanation following the structure above

Keep it concise. Lead with the "what": the reader wants to orient before diving into "why" and "how."