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name: spindle description: "Stage N2. Rapid classification bursts — sorting, tagging, filtering fragments. The workhorse stage at ~45% of cycle time. Most fragments die here." context: fork user-invocable: false allowed-tools:

• Read

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Spindle — Stage N2

The sorting room. Takes the noisy fragment bag from drift, classifies each fragment, kills irrelevant noise, extracts themes.

Inputs

From orchestrator: fragment_bag (from N1), target_skill (path), selectivity (0-1, default 0.6), cycle_number.

Procedure

1. Load Target Skill

Read SKILL.md. Build mental model of: what it does, what it handles, what it assumes, what it declines.

2. Classify Each Fragment

One category + one signal strength (0-1) per fragment:

| Category | Code | Description | |----------|------|-------------| | Direct hit | HIT | Skill explicitly covers this | | Edge case | EDGE | Within domain but near boundaries | | Gap | GAP | Within domain but NOT covered | | Friction | FRIC | User difficulty with documented workflow | | Adjacent | ADJ | Related domain, different skill | | Noise | NOISE | Irrelevant or unrealistically synthetic |

3. Filter

Survival threshold = selectivity × 0.8. Exceptions:

• FRIC and GAP survive at signal > 0.3 (always interesting)
• Synthetic fragments get +0.1 bonus (give creativity a chance)

| Cycle | Selectivity | Expected Kill Rate | |-------|------------|-------------------| | 1 | 0.7 | 60-70% | | 2 | 0.5 | 40-50% | | 3 | 0.3 | 20-30% | | 4+ | 0.2 | 10-20% |

4. Extract Themes

If 2+ fragments touch the same area, elevate to a theme with priority (high/medium/low). Themes are primary input for N3.

Flag contradictions (skill declines something users expect) and escalations (fundamental structural issues).

5. Output Sorted Manifest

sorted_manifest:
  target_skill: /path/to/SKILL.md
  input_fragments: 14
  surviving_fragments: 6
  kill_rate: 0.57
  themes: [{name, fragment_ids, priority, reason}]
  survivors: [{id, category, signal, content, tags, theme, notes}]
  discarded: {count, categories: {NOISE: 4, ADJ: 2, HIT: 2}}
  escalations: []

Behavioral Rules

• Be decisive. If you can't classify quickly, it's NOISE.
• Favor false positives. Better to pass mediocre fragments to N3 than kill one that would have produced insight in REM.
• Don't generate. Spindle classifies, it doesn't create new fragments.