TrueAlpha Factor Acceptance Protocol

Core Axiom (AGENTS.md & init.md): "A constant never stands in for a measurement. Never overwrite a point-in-time record. Never put computation logic outside common/factors. Factor inputs are provenance-neutral typed records. Composite confidence cannot exceed the minimum consumed confidence."

1. When to Activate This Skill

• When designing, reviewing, or modifying any factor module in common/factors.
• When adding or reviewing composite factor definitions (such as three-tier valuation, strategy evaluators).
• When validating factor outputs against ground-truth datasets.

2. Mandatory Verification Checklist

1. Point-in-Time & Measurement Integrity

• Dual Timestamps: Distinguish valid_time from transaction_time (knowable-at).
• No Clock Defaults: transaction_time must come from an explicit source property, never an insertion-clock default (now()).
• No Hardcoded Constants: Universe size, obligation count, denominator cells (never hardcode 84 cells!), growth window, freshness, and confidence scores (never stamp 0.85, 0.92, or 1.00) must be derived from the run and the continuous 0-100 confidence model (source prior x agreement x freshness x lineage), not hardcoded.
• Decimal Monetary Arithmetic: Use Decimal with explicit rounding context (ROUND_HALF_EVEN) for monetary values; binary floating point (float) is strictly prohibited.

2. Degenerate & Missing Data Gating

• Explicit Gaps Beat Silent Drops: If data is missing or unsourced, return value=None with an explicit reason code (e.g. growth_convention_unsourced:analyst_consensus), never substitute 0, a sentinel, or a silent default.
• Corporate Action Awareness: Per-share metrics (like EPS) must not be compared across stock splits without split adjustment. When corporate actions are unadjusted, net income must anchor growth rates.

3. Composite Factor Rules (Module 7)

• Confidence Bounding: Composite factor confidence must satisfy: $$\text{confidence}{\text{composite}} \le \min{i}(\text{confidence}_{\text{input}_i})$$
• Availability & Score Propagation: Every computed value is served (available) alongside its continuous 0-100 confidence score (High $\ge 80$, Medium $60\text{–}79$, Low $< 60$). Low confidence lowers the composite score; it never silently drops or blocks the row.
• Materialized Inputs Only: Composite factors reload materialized upstream factor results from mart; they never branch on raw source vendors or bypass the mart layer.

4. Standing Checks (skills smoke and close)

• Whole Scope Covered: Every deliverable in the issue scope has a standing check.
• Reproducible Red: Confirm the check goes RED against the unfixed code before declaring victory.
• Fail Where Production Calls: Test passes data through the exact deployed call signature.