deep-discovery

name	deep-discovery
description	Use after the product spec is approved, before any implementation work. Pressure-tests the spec with a 100-question self-interrogation where each question builds on the previous answer. Returns critical issues, strengths, and a revised proposal. Material revisions loop back to brainstorming.

Announce on entry

I'm using the deep-discovery skill to pressure-test the approved product spec with a 100-question interrogation before any implementation work. Material revisions will loop back to brainstorming.

Purpose

A brainstorming spec ships the best version of what the human partner and the agent could think of while co-writing it. Deep-discovery is the adversarial pass: one hundred questions, each building on the previous answer, hunting for assumptions, edge cases, missing requirements, and failure modes that the authoring frame could not see. The output is structured findings, not prose; findings that are material loop back to brainstorming for a spec revision.

Precondition

• An approved product spec exists at docs/leyline/specs/YYYY-MM-DD-<topic>-design.md.
• If Surfaces is anything other than none, the UX spec from design-brainstorming also exists at docs/leyline/design/YYYY-MM-DD-<topic>-ux.md and is approved. (deep-discovery targets the product spec; the UX spec is pressure-tested by design-interrogation in 2b.)

Hard gate

Do NOT run a 100-question pass, document findings, or advance to any successor
skill until both preconditions are satisfied: (1) the product spec exists at the
stated path, AND (2) the human partner has explicitly approved it. If either
fails, STOP. Route the first back to `brainstorming`; surface the second to the
human partner and wait for approval. This applies to EVERY project regardless
of perceived simplicity or obviousness.

Violating the letter of the rules is violating the spirit of the rules.

When to use

digraph when_to_use {
    "Product spec approved" [shape=doublecircle];
    "UX spec required and approved?" [shape=diamond];
    "deep-discovery (2a)" [shape=box];
    "Block; return to design-brainstorming" [shape=box];

    "Product spec approved" -> "UX spec required and approved?";
    "UX spec required and approved?" -> "deep-discovery (2a)" [label="yes, or Surfaces=none"];
    "UX spec required and approved?" -> "Block; return to design-brainstorming" [label="no"];
}

deep-discovery runs on every project regardless of scope. Skipping 2a because "the spec is obviously right" is the exact failure mode the pass exists to prevent.

Process

digraph deep_discovery_flow {
    Start [shape=doublecircle, label="Approved spec(s) in hand"];
    Dispatch [shape=diamond, label="Subagent dispatch available?"];
    Subagent [shape=box, label="1. Dispatch fresh subagent with 100-question-prompt.md"];
    Inline [shape=box, label="1. Run 100-question pass inline in this session"];
    Report [shape=box, label="2. Receive structured report (Critical / Strengths / Revised)"];
    Present [shape=box, label="3. Present report to the human partner"];
    Material [shape=diamond, label="4. Material revisions?"];
    LoopBack [shape=box, label="Loop back to brainstorming; update spec; re-approve"];
    Document [shape=box, label="Document findings in spec; mark '2a pass complete' "];
    Next [shape=diamond, label="5. Surfaces != none and scope warrants 2b?"];
    InvokeDesign [shape=box, label="Invoke design-interrogation (2b)"];
    InvokeIsolate [shape=box, label="Invoke using-git-worktrees (3)"];
    End [shape=doublecircle, label="Successor named"];

    Start -> Dispatch;
    Dispatch -> Subagent [label="yes"];
    Dispatch -> Inline [label="no"];
    Subagent -> Report;
    Inline -> Report;
    Report -> Present -> Material;
    Material -> LoopBack [label="yes"];
    LoopBack -> Start [label="after re-approval"];
    Material -> Document [label="no"];
    Document -> Next;
    Next -> InvokeDesign [label="yes"];
    Next -> InvokeIsolate [label="no, document 2b skip"];
    InvokeDesign -> End;
    InvokeIsolate -> End;
}

Checklist

Create one task entry (TodoWrite or harness equivalent) per item.

1. Dispatch, or run inline only as a fallback. If the harness supports subagent dispatch, dispatch a fresh subagent with the contents of 100-question-prompt.md and the absolute path to the product spec. Do not paraphrase the prompt; use the template verbatim.

   "Supports dispatch" means the primitive exists in the harness. Token pressure, rate limits, and session length are NOT reasons to fall back to inline. The subagent is bias-free by construction; the inline path inherits session bias and produces a lower-confidence report. Fall back to inline only when dispatch is literally unavailable, and say so out loud when you do.

2. Consume the structured report. The output has three sections: Critical Issues, Strengths, Revised Proposal. Do not edit the report; record it as returned.

3. Present to the human partner. Show the full report. Do not triage silently. Do not hide findings you disagree with.

4. Classify, then decide. Before calling any round material or non-material, tag each Critical Issue with exactly one of these literal letter tags:

   • (S) Structural - a named approach, constraint, goal, non-goal, or dependency in the product spec cannot survive the finding as written. Always material.
   • (O) Operational - a runtime, scale, security, observability, rollback, migration, or on-call concern the spec does not address. Always material.
   • (R) Second-order refinement - internal-consistency fix between edits made in rounds 1..N-1, or sub-line clarity inside those edits. Not material.
   • (E) Editorial - terminology, phrasing, or naming inside the existing approach. Not material.

   Tags are recorded verbatim in the spec under a "Round classification" subsection as literal (S), (O), (R), (E) prefixes on each finding. Prose-embedded dismissal ("this one is cosmetic, this one is editorial") is insufficient; the tags must be the literal letters.

   Then:

   • Material (at least one (S) or (O)): loop back to the correct Discovery co-skill. If the material finding is product-domain, loop to brainstorming. If UX-domain (voice, flow, state, accessibility target, IA), loop to design-brainstorming. Name the target explicitly when announcing: "Deep-discovery surfaced material <product | UX>-domain revisions; returning to <brainstorming | design-brainstorming> to update the spec and re-obtain approval." Do not proceed.

   • Convergence candidate (all (R) or (E)): present the per-finding classification, the count trend across rounds 1..N, and a completion-or-continue recommendation to the human partner with reasoning. The human partner decides. Do NOT append the completion marker without explicit human-partner approval, even when the human partner has delegated the call in advance. Delegation authorizes the recommendation and the classification work; the classification is what the human partner reviews, and that review is what authorizes the marker. If the human partner is unreachable, wait. "Unreachable" is categorical and duration-independent: any absence during which the human partner cannot review the classification right now counts, whether the absence is a scheduled meeting, a flight, a step-out, an indefinite vacation, or anything else. A two-hour meeting and a two-week vacation both require you to wait; the duration of the absence does not scale the authorization. Round-count claims ("we have run it N times"), aggregate-trend appeals ("the pattern argues against it"), convergence metaphors ("noise floor", "editorial whack-a-mole", "chasing the wake of our own edits"), and reachability-gradient appeals ("a scheduled absence is different from real unreachability") are all substitutes for the per-finding review; none of them authorizes the marker.

   Verbatim completion-marker (appended only after explicit human-partner approval):

   Deep-discovery pass complete - round <N> - YYYY-MM-DD
   

5. Transition.

   • If Surfaces is not none AND scope warrants 2b, invoke design-interrogation (stage 2b). Scope rules (full rules in design-interrogation/SKILL.md): required for multi-screen-ui, cross-platform, or any UX spec whose state matrix covers more than one surface; optional for complex single-screen-ui / cli-only / developer-facing with non-trivial error paths; skipped otherwise.
   • If 2b is skipped, document the skip verbatim in the UX spec (design-interrogation skipped - scope: <reason>) and invoke using-git-worktrees (stage 3).

The 100-question pass (invariants)

• Each question builds on the previous answer. Do not reset context between questions.
• The pass covers, across its 100 questions, at minimum these dimensions (keep this list synchronized with 100-question-prompt.md):
  • Assumptions (what is taken for granted?)
  • Failure modes (what breaks, and with what blast radius?)
  • Missing requirements (what is implied but not stated?)
  • Dependencies (internal and external)
  • Constraints (technical, organizational, regulatory, timeline)
  • Alternatives rejected (are the rejections sound?)
  • Edge cases (input extremes, empty states, concurrency)
  • Scale boundaries (at what volume does the design break?)
  • Rollback paths (how do we undo this if it ships and hurts?)
  • Testing strategy (how do we know it works?)
  • Observability (how do we know it works in production?)
  • Security (threat model, secrets, authn/authz, data exposure)
  • Operational concerns (runbooks, on-call, deploys)
  • Team / ownership (who maintains this?)
  • Timelines (is the schedule realistic?)
  • Cost and unit economics at target scale
  • Migration / backfill path for stateful features
  • Success criteria (observable, measurable)
  • Known-unknowns (what do we know we do not know?)
• Question weight is not uniform. If an answer opens a larger problem, the next N questions follow that thread.
• No question is off-limits. Soft questions ("is this worth doing?") are on the table.

Deep-discovery is not a checklist of dimensions; it is an adversarial conversation that covers those dimensions in the course of building on each answer.

Report format (required)

The report the subagent returns, or the agent produces inline, has exactly three sections:

## Critical Issues
- <finding>: <file-path-and-line-or-section reference> - <why it matters>

## Strengths
- <finding>: <what the spec got right, worth preserving>

## Revised Proposal
<A short proposal - not a rewrite - naming the changes the spec should adopt to address the Critical Issues. Grouped by file and section.>

If a section has no entries, write "None." Do not skip the section.

Anti-patterns

• "The Spec Is Obviously Right, Skip The Pass" - the pass exists to catch obviously-right specs that later surprise on contact with reality.
• "I'll Ask Ten Questions, That's Enough" - the 100-question process is the process. Stopping early is agreeing with the spec without having tested it.
• "The Subagent Was Too Harsh, I'll Soften The Report" - the report is the report. Present it. The human partner decides what to act on.
• "The Finding Is Valid But Not Material" - be honest. If a named approach, constraint, goal, or non-goal cannot survive the finding as written, it is material. Hiding it as a non-material suggestion is rationalization.
• "The Revision Is Small, I'll Edit The Spec And Skip Re-Approval" - re-approval is cheap. Silent edits on an approved spec break the gate.
• "Subagents Are Available But I'll Run Inline To Save Time" - subagents are bias-free by construction; inline runs inherit session bias. Dispatch unless the primitive is literally unavailable.
• "Reframe The Finding As A Strength" - if a finding identifies a risk or gap, it stays in Critical Issues. Noting that the spec "acknowledged" the risk does not neutralize it.
• "I'll Run It After The Next Step" - the next step is blocked until 2a completes. No exception.
• "Every Round Is Material Because I Keep Finding Something" - if rounds N and N+1 produce only (R) and (E) findings, the spec has converged on substance. Looping on "there's always something" is structurally identical to "I'll Ask Ten Questions" - both skip the skill's actual judgment criterion. Classify each finding per step 4; if none is (S) or (O), the round is a convergence candidate, not automatic material.
• "Delegation Authorizes The Action, Not Just The Recommendation" - when the human partner says "make the call, I'll back it," the delegation covers producing the classification and the recommendation, not the unilateral marker append. The human partner's review of the classification is what authorizes the marker. Acting without the review, even with delegation in hand, is the structural failure this skill exists to prevent.
• "Delegation Is Ongoing Authorization, Not Pre-Paid Consent" - "make the call, I'll back it" authorizes the classification and recommendation work, redeemed at the moment the human partner reviews the result. It is not a consent transaction already completed; the human partner cannot consent to a classification they have not seen. Framing delegation as pre-paid consent ("they've already signed off", "the human partner already ate the cost of not reviewing") is a category error that treats authorization as transferable in advance, when the skill requires it to flow through the review step.
• "Convergence-Metaphor Substitutes For Classification" - "noise floor", "asymptote", "editorial whack-a-mole", "chasing the wake of our own edits" are all ways to generalize across findings without classifying each one. Apply the (S) / (O) / (R) / (E) tags literally and individually. The metaphor may be true; the tags are what the human partner reviews.

Red flags

Thought	Reality
"The human partner just approved this; I'll come back to interrogation later"	Later means never. Run it now while the spec is fresh.
"The spec is small, 20 questions is fine"	Small specs produce small reports, not short passes. The value is the chain.
"Most findings are cosmetic, no need to present"	Present anyway. The human partner judges materiality, not you.
"I'll dispatch the subagent without a path to the spec"	The subagent has no context. Constructed context is the entire prompt.
"The subagent disagreed with the spec; that's bias"	The subagent is bias-free by construction. You are biased toward the spec you just helped approve.
"Seven rounds is a lot; surely we can stop"	Round count is not the exit criterion; finding-character is. Classify each Critical Issue per step 4.
"Every round finds something material"	Check the tags: (S) / (O) are material, (R) / (E) are not. Finding something is not the same as finding something material.
"The human partner delegated the call, so I'll append the marker"	Delegation covers the classification and the recommendation. The human partner's review of the classification authorizes the marker. Present; wait.
"Deferring under delegation is abdication"	Deferring without the classification would be. Deferring with the classification presented is the skill's required shape.
"The pattern is clear; I don't need to tag each finding individually"	The tags ARE the pattern, applied at the level the skill operates on. Prose-embedded classification doesn't survive review.
"A two-hour meeting isn't really unreachable; the rule means indefinite absences"	Unreachable is categorical and duration-independent. If the human partner cannot review the classification right now, wait — regardless of how long "right now" lasts.
"They already said 'make the call', that's pre-paid consent"	Delegation authorizes the recommendation and the classification work. The human partner's review of the classification is what authorizes the marker. Consent cannot be pre-paid on something not yet seen.

Forbidden phrases

Do not say:

• "Quick pass" - 100 questions is not quick.
• "Rough interrogation" - the shape is the value; there is no rough version.
• "Skipping deep-discovery, the spec is clear" - if the spec is clear, the pass takes less time and finds less. It still runs.
• "Abbreviated 100-question pass" - 100 is the floor, not the ceiling.
• "High-level interrogation" - the chain is the product, not the summary.
• "I'll just hit the key dimensions" - dimensions are covered by chains, not by checklist.
• "The spec is small so the chain will be short" - small specs produce shorter reports, not shorter chains.
• "Editorial whack-a-mole" - cluster-level dismissal that substitutes for per-finding classification.
• "We are in the noise floor" - convergence metaphor that skips the per-finding review.
• "The pattern argues against it" - aggregate-trend appeal used as an exit criterion instead of finding-character classification.
• "Abdication dressed as caution" - frames the skill's required deferral to the human partner as weakness.
• "Seven full passes is empirically adequate" (or any N-passes-is-enough variant) - round-count appeal substituted for classification.
• "Appending the completion marker" (without the immediately preceding per-finding (S) / (O) / (R) / (E) classification and explicit human-partner approval).
• "The delegation was pre-paid consent" - transactional-consent framing of delegation.
• "The human partner already ate the cost of not reviewing" - same transactional-consent framing.
• "A two-hour wait is a rounding error" (or any duration-weaponization variant) - uses absence duration to scale the authorization.
• "A scheduled absence is different from real unreachability" - smuggles a reachability gradient into a categorical rule.

Output artifacts

• The structured report (Critical Issues / Strengths / Revised Proposal) appended to or referenced by the spec.
• If material revisions surface, the spec is updated (by brainstorming) and committed with a short note: "deep-discovery round N applied".

Supporting files

• 100-question-prompt.md - the prompt template the subagent receives, or the inline runner follows.
• report-template.md - blank three-section report for authors to fill when running inline.

Successor

If Surfaces is not none AND scope warrants 2b:

Invoking design-interrogation (stage 2b). The product spec is cleared; pressure-testing the UX spec next.

Otherwise:

Invoking using-git-worktrees (stage 3). Interrogation cleared. 2b skip documented in the spec as: design-interrogation skipped - scope: .

Missing-successor fallback

If design-interrogation or using-git-worktrees is not present in this version of the plugin, STOP. Tell the human partner the pipeline is incomplete and which skill is missing. Do not improvise; do not skip ahead.

Do not exit without naming and invoking the named successor.