/diagnose

<purpose> Diagnose before fixing. The debug skill exists but no command orchestrates it. Mixing diagnosis with implementation means the surgeon starts cutting before the X-ray. /kernel:diagnose is the X-ray. </purpose>

<skill_load> Load: skills/debug/SKILL.md, skills/testing/SKILL.md, skills/architecture/SKILL.md </skill_load>

<modes> <mode id="bug" default="true"> <trigger>error, failing test, stack trace, "not working", exception, crash</trigger> <steps> <step id="reproduce"> Read error output, failing test, or stack trace. Run the failing command/test to confirm reproduction. If not reproducible, document conditions and ask for more info. </step> <step id="trace"> Follow the call stack from error to origin. Check recent git changes: git log --oneline --since="3 days" -- {affected files} Identify when the behavior changed. </step> <step id="isolate"> Run failing test in isolation (not full suite). If multiple tests fail, find the minimal reproduction. Binary search: comment out code blocks to narrow the cause. </step> <step id="hypothesize"> Form 2-3 hypotheses for root cause. For each hypothesis: what evidence would confirm or reject it? Test each hypothesis with minimal code changes or debug output.

    <ask_user>
      Use AskUserQuestion when: hypotheses formed and user may have domain knowledge
      Ask: "Top hypothesis: {hypothesis}. Does this match what you're seeing, or is there context I'm missing?"
      Options: investigate that, I have more context, try a different hypothesis
    </ask_user>
  </step>
  <step id="diagnose">
    Identify confirmed root cause.
    List affected files and blast radius.
    Recommend fix approach (don't implement yet).
    Determine tier based on blast radius.
  </step>
  <step id="handoff">
    Output structured diagnosis.
    Hand off to /kernel:ingest or /kernel:forge for implementation.
    If the user wants to fix immediately, transition to execute mode.
  </step>
</steps>

</mode> <mode id="refactor"> <trigger>refactor, restructure, "clean up", "simplify", coupling, dependency</trigger> <steps> <step id="map"> Identify all files/modules touched by the refactor target. Use Grep/Glob to find all references. Build a dependency map of what imports/calls what. </step> <step id="trace_deps"> For each file in the map: who calls this? who depends on it? What breaks if this changes? Identify the blast radius. </step> <step id="measure_coupling"> How tangled is this code with the rest of the system? Count cross-module references. Identify circular dependencies. </step> <step id="risks"> What are the edge cases in the current implementation? What tests exist? What's untested? What invariants must be preserved? </step> <step id="diagnose"> Produce restructuring plan with safety constraints. List files that change, in what order. Identify tests that must pass before AND after. Determine tier based on file count. </step> <step id="handoff"> Output structured diagnosis. Hand off to /kernel:ingest with pre-identified scope. </step> </steps> </mode> </modes>

<output_format>

Diagnosis: {title}

Mode: bug | refactor Root cause: {one sentence} Confidence: high | medium | low

Affected Files

File	Role
{path}	origin — where the bug lives / refactor starts
{path}	downstream — affected by the change

Blast Radius

{N} files affected. Tier {1|2|3}.

Hypotheses Tested (bug mode)

1. "{hypothesis}" → CONFIRMED | REJECTED ({evidence})

Dependency Map (refactor mode)

{what depends on what}

Recommended Approach

{what to do, not how — that's for ingest/forge}

Tests Required

• {test that must pass before the fix}
• {test that validates the fix}

---

Next: /kernel:ingest or /kernel:forge to implement. </output_format>

<telemetry> Record diagnosis event: agentdb emit command "diagnose" "" '{"mode":"bug|refactor","confidence":"high|medium|low","blast_radius":N,"tier":N}' </telemetry>