explain

name	explain
description	Compare 2-3 approaches to a coding or design decision with trade-offs and a recommendation. Teach-first framing — surfaces decision complexity rather than picking for you. For "which way should I..." questions (complements /chiron which handles "how do I..." questions). Defers to CLAUDE.md or AGENTS.md.
user-invocable	true
argument-hint	[design decision or 'which way' question — omit to infer from conversation]
allowed-tools	Read, Grep, Glob, LS
compatibility	Run /teach-chiron first to generate .chiron-context.md

/explain — compare approaches with trade-offs

Quick start:

• /explain REST vs gRPC for this service — compare two named options
• /explain how should I handle retries? — explore a design question
• /explain — no argument: infer the decision point from the current conversation

Step 0 — Load project context

Check if .chiron-context.md exists in the project root. If it exists: read it. DO NOT scan the codebase or read additional files unless the user's question references a specific file. If not: tell the user: "No project context found. Run /teach-chiron first." Then stop.

The user's question or decision:

$ARGUMENTS

If $ARGUMENTS is empty or whitespace-only: derive the decision point from the current conversation instead of asking the user to restate it. Scan the recent turns for a visible choice — "should we use A or B", "I'm torn between X and Y", "not sure which pattern fits", "wondering whether to …" — or any discussion where two or more approaches are being weighed. Open with a one-line confirmation: "Inferring decision from conversation: . Say otherwise and I'll retarget." Then run the normal decision tree with that question in place of $ARGUMENTS.

Inference rules:

• Prefer an explicit comparison ("A vs B") over an implicit one. If both are present, use the most recent.
• If the user named the options themselves, preserve those exact option names in the inferred question.
• If the conversation is about implementing a specific approach (not choosing between several), redirect: "That reads like a how-to — try /chiron instead." Do not convert an implementation question into a comparison.
• If no decision point is visible, stop with: "No decision point visible in conversation — try /explain <A vs B> or /explain <question>."
• Never fabricate a decision or invent options that weren't discussed. Ambiguity → ask, don't guess.

CRITICAL — user instructions always win

If the current project's CLAUDE.md or AGENTS.md conflicts with the behavior below, follow those instructions instead. This command is opt-in; the user invoked it explicitly.

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Current level

Apply the voice level from .chiron-context.md. If missing or unrecognized, use default.

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What this command does

Given a coding or design question with multiple plausible approaches, /explain surfaces 2–3 named approaches with trade-offs, then gives a recommendation qualified to the user's specific situation. It's the answer to "which way should I..." questions rather than "how do I..." questions (which /chiron handles).

Scope:

• 2–3 approaches — never more. More choices means less signal. Pick the 3 most representative.
• Each approach has: one-sentence description, 2–3 pros, 2–3 cons, one-sentence "when to use".
• Recommendation is qualified — "for the case you described" — not absolute.
• Closing handoff to /chiron for implementation of the chosen approach.

Decision tree

0. Is $ARGUMENTS empty? Infer the decision point from the conversation per the rules above. If inference succeeds, announce the inferred decision in one line, then continue at step 1 with that question. If inference fails (no decision point visible, or the conversation is about implementation), stop with the fallback message — do not invent a comparison.
1. Is this actually a "which approach" question? If the user asked "how do I implement X" (single well-defined task), route to /chiron instead. Respond: "This looks like a 'how do I' question — try /chiron <your question> for step-by-step guidance. /explain is for choosing between multiple valid approaches."
2. Are there actually 2+ valid approaches? If only one approach is valid for the stated case, skip the comparison format. Give a direct one-approach recommendation with a brief explanation of why the alternatives don't fit.
3. Is the question under-specified? If you can't identify 2 approaches without more context (e.g., /explain error handling — depends heavily on language, app type, error semantics), ask 1–2 clarifying questions before presenting approaches. Don't invent context.

Response format — keep it terse

Compact output format. Three approaches on ~5 lines each instead of decorative headers and bold labels:

Approaches:

1. <Approach name> — <one-line description>
   + <pro>, <pro>, <pro (optional)>
   - <con>, <con>, <con (optional)>
   When: <one sentence>

2. <Approach name> — <one-line description>
   + <pro>, <pro>
   - <con>, <con>
   When: <one sentence>

3. <Approach name> — <one-line description>  [optional, only include if genuinely distinct]
   + <pro>, <pro>
   - <con>, <con>
   When: <one sentence>

Recommend: <approach X> by default. <approach Y> when <condition>. <approach Z> when <condition>.

Implementation? `/chiron <request>`

Example (shape reference, not content to copy):

Approaches:

1. errgroup.WithContext — stdlib-adjacent, cancel-on-first-error built in
   + familiar API, automatic context cancellation, composable with existing middleware
   - no built-in concurrency limit, requires external semaphore for bounded parallelism
   When: most Go fan-out tasks where you want cancel-on-error semantics

2. Manual goroutines + sync.WaitGroup — full control, no dependencies
   + zero dependencies, explicit lifecycle, easy to add custom recovery logic
   - manual error collection, no cancel propagation, easy to leak goroutines
   When: simple fire-and-forget tasks where errors are logged, not propagated

3. Worker pool with buffered channel — bounded concurrency by design
   + natural backpressure, fixed memory footprint, predictable resource usage
   - more boilerplate, harder to wire cancel-on-error, channel sizing requires thought
   When: high-volume input where unbounded goroutines would exhaust resources

Recommend: errgroup by default. Worker pool when input volume is unbounded. Manual WaitGroup only for fire-and-forget logging.

Implementation? `/chiron implement fan-out with errgroup`

Style rules:

• One line per pros/cons bullet, comma-separated items, not multi-line markdown lists
• + / - / When: prefixes instead of **Pros:** / **Cons:** / **When to use:** labels
• No decorative ## headers for each approach — numbered list is enough
• No padded framings like "Three main approaches, each with clear trade-offs:" — just "Approaches:"
• Closing handoff is one line, no extra explanation

Pre-delivery checklist (verify silently)

1. Exactly 2–3 approaches — not 1 (use /chiron instead), not 4+ (too many choices)
2. Each approach has pros AND cons — no approach is presented as all-upside
3. Recommendation is qualified by context, not absolute
4. Handoff line to /chiron is present
5. No fence-sitting — a clear recommendation exists for the stated case

Teaching dial effects on /explain: Read teaching.depth and teaching.theory_ratio from .chiron-context.md. If missing, use defaults (5, 3).

• depth 8–10: expand each approach from ~5 lines to ~8 lines; include a "deeper context" note about when each approach historically emerged.
• theory_ratio 8–10: add a brief "theory note" after the recommendation naming the underlying design principle (e.g., "This is the Single Responsibility Principle applied to data flow").
• At default values (5, 3), no expansion — standard compact format.

Idiom callouts

When naming a specific primitive or library in an approach, offer ONE short doc pointer (the "read this first" pattern):

"Approach 1: use errgroup.WithContext from golang.org/x/sync/errgroup. Background: pkg.go.dev/golang.org/x/sync/errgroup."

One pointer per named primitive, no more. If you name 3 primitives in 3 approaches, that's 3 doc pointers total.

Anti-patterns — what NOT to do

1. Do not moralize. Never say "the right way is" or "you should" — present trade-offs and let the user decide.
2. Do not refuse to ship a direct answer when asked. If the user says "just tell me which one" or "skip the comparison", give your recommendation immediately without the full compare-and-contrast. Anti-pattern #2 applies.
3. Do not present more than 3 approaches. More choices = less signal. Pick the 3 most representative; mention that others exist in the recommendation section if relevant.
4. Do not fence-sit. Every response must end with a recommendation. "It depends" is not a recommendation. If context matters, STATE the contexts and give a recommendation per context.
5. Do not pollute artifacts. Zero teaching content in any file edits this command produces.

Level rules — voice tone per level

Read ~/.chiron/config.json at invocation time. The level affects the voice tone of the comparison and recommendation. The 2–3 approach structure is the same at every level.

gentle

• Voice: warmer, explicit "all are valid" framing. Softens cons bullets ("something to watch for" instead of "bad because").
• Recommendation: offered as one option among several, user empowered to pick.
• Example framing: "A few solid approaches here — each has its place. Let me walk through them..."

default

• Voice: A+B blend (v0.1 baseline). Neutral, comparative.
• Recommendation: direct but qualified by context.
• Example framing: "Three main approaches, each with clear trade-offs."

strict

• Voice: terse, bullet-heavy, opinionated. Recommendation is blunt.
• No "all are valid" language — some approaches are objectively worse for the stated case; say so.
• Example framing: "Three approaches. Approach 1 is canonical. The others have narrow use cases."

Inviolable at every level

• Anti-pattern #2: never refuse to ship when asked. If the user says "just tell me", skip the compare-and-contrast and give the recommendation directly.
• No moralizing at any level.
• Recommendation is mandatory — fence-sitting is disallowed at every level.
• CLAUDE.md overrides win at every level.

Response shape — summary

1. Read ~/.chiron/config.json for voice level.
2. Decision tree: is $ARGUMENTS empty (→ infer from conversation)? Is this a "which approach" question? Route elsewhere if not.
3. Identify 2–3 valid approaches; if under-specified, ask clarifying questions first.
4. Present each approach with pros/cons/when-to-use in the format above.
5. Close with a qualified recommendation and a handoff to /chiron for implementation. If the user seems unfamiliar with the topic, suggest /tour <topic> first for background reading.
6. Do NOT write to ~/.chiron/profile.json. This command is read-only.