Auditing Intelligence-Context Fit
The Multiplicative Model
output_quality = reasoning_tier × context_quality
This is multiplicative. A mismatch in either dimension degrades output non-linearly:
| Reasoning Tier | Context Quality | Output |
|---|---|---|
| High | High | Excellent |
| High | Low | Mediocre (model can't compensate for bad retrieval) |
| Low | High | Mediocre (model can't leverage complex context) |
| Low | Low | Poor |
| Low | Very High (long, complex) | Harmful — model hallucinates connections in complex context it can't parse |
The last row is the "long context + weak reasoning = harmful output" failure. It's worse than simply poor because the model generates confident-sounding wrong answers.
The Degradation Curve
As context complexity increases beyond a model's reasoning ceiling:
- Phase 1 — Normal operation: Model handles context well; output quality matches expectation
- Phase 2 — Reasoning plateau: Model is at capacity; quality stops improving even as context improves
- Phase 3 — Context poisoning: Additional context overwhelms the model; it begins drawing spurious connections; quality degrades
- Phase 4 — Expensive RAG fallback: System compensates by adding more retrieval passes, reranking, and chain-of-thought prompting — all of which add cost without fixing the root mismatch
Symptom of Phase 3–4: "We added better context and the answers got worse, so we added more prompting."
flowchart LR
P1["Phase 1\nNormal Operation\nQuality ✓"] -->|complexity grows| P2["Phase 2\nReasoning Plateau\nQuality flat"]
P2 -->|more context added| P3["Phase 3\nContext Poisoning\nQuality ↓\nSpurious connections"]
P3 -->|team compensates| P4["Phase 4\nExpensive RAG Fallback\nCost ↑↑ Quality unchanged"]
style P1 fill:#dcfce7,stroke:#22c55e
style P2 fill:#fef9c3,stroke:#eab308
style P3 fill:#fed7aa,stroke:#f97316
style P4 fill:#fee2e2,stroke:#ef4444
The Fit Matrix
quadrantChart
title Intelligence-Context Fit — Output Outcomes
x-axis "Low Model Tier (Haiku)" --> "High Model Tier (Opus)"
y-axis "Simple Context (L1–2)" --> "Complex Context (L4–5)"
quadrant-1 "Optimal: excellent output"
quadrant-2 "Over-resourced: high cost, correct output"
quadrant-3 "Cost-efficient: correct output"
quadrant-4 "Harmful: confident wrong answers"
Haiku + Factual: [0.15, 0.15]
Sonnet + Relational: [0.5, 0.5]
Opus + Causal: [0.85, 0.85]
Haiku + Causal: [0.15, 0.85]
Opus + Factual: [0.85, 0.15]
The Audit Framework
Step 1: Classify Context Complexity
Rate the complexity of the context being passed to the model on this scale:
| Level | Description | Example |
|---|---|---|
| 1 — Factual | Single documents, direct lookup | "What does policy X say?" |
| 2 — Comparative | Multiple documents, explicit comparison | "Compare options A, B, C" |
| 3 — Relational | Cross-document entity relationships | "What teams are affected by X?" |
| 4 — Temporal | Events across time, sequence reasoning | "How did this evolve over 6 months?" |
| 5 — Causal | Multi-hop causal chains | "What chain of decisions led to Y?" |
Step 2: Assess Model Reasoning Tier
| Tier | Model Examples | Appropriate Context Complexity |
|---|---|---|
| Basic | Claude Haiku 4.5 | Level 1–2 |
| Mid | Claude Sonnet 4.6 | Level 1–4 |
| Advanced | Claude Opus 4.6 | Level 1–5 |
Note: Model capability evolves rapidly. Retest your tier assignments when new model versions release.
Step 3: Identify the Mismatch
Scenario A: Context too complex for model tier
- Symptom: Confident but incorrect answers; spurious causal claims; inconsistent reasoning across runs
- Fix: Upgrade model tier OR simplify context (decompose into sub-queries at lower complexity levels)
Scenario B: Model over-qualified for context
- Symptom: Correct output but unnecessarily high cost and latency
- Fix: Downgrade model tier for this query class; reserve advanced models for Level 4–5 queries
Scenario C: Context quality is the bottleneck, not model
- Symptom: Upgrading the model doesn't improve output; answers are plausible but missing key facts
- Fix: Improve retrieval pipeline (check
diagnosing-rag-failure-modes); model is not the constraint
Scenario D: Context volume exceeds model window effectively
- Symptom: Model ignores content from the middle of long contexts; only uses beginning/end
- Fix: Apply windowed compression (see
temporal-reasoning-sleuth); reduce context length, not model
Step 4: Prescribe the Fix
| Mismatch | Fix |
|---|---|
| High complexity, low-tier model | Upgrade model OR decompose query |
| Low complexity, high-tier model | Route to lower-tier model |
| Poor retrieval → poor context | Fix retrieval pipeline (not the model) |
| Context too long for model | Apply windowed compression |
| All tiers failing on one query type | Structural mismatch — needs hybrid architecture |
Common Anti-Patterns
Anti-Pattern: Haiku + Organizational History
Using a basic-tier model on Level 4–5 context complexity. The model confidently fills gaps it cannot reason over. The output looks plausible but contains fabricated causal connections.
Fix: Reserve causal/temporal queries for Sonnet or Opus tier. Use Haiku only for factual lookup (Level 1–2).
Anti-Pattern: Opus on Simple RAG Lookups
Using an advanced-tier model for point-query factual retrieval. Correct output, but 5–10× the cost and latency of an appropriate tier.
Fix: Route Level 1–2 queries to Haiku; reserve Opus for Level 4–5 queries where reasoning depth matters.
Anti-Pattern: Compensating with More Prompting
When output quality degrades, adding more system prompt, chain-of-thought instructions, and few-shot examples to compensate for a model-context mismatch. This adds cost and complexity without fixing the root cause.
Fix: Identify which step of the audit framework is the actual mismatch and fix it there.
Output: Fit-Audit Report
INTELLIGENCE-CONTEXT FIT AUDIT
================================
System / Query Class: [what you're auditing]
Context Complexity Level: [1–5] — [description of why]
Current Model Tier: [Haiku / Sonnet / Opus]
Observed Symptom: [what's going wrong]
Mismatch Type: [Scenario A / B / C / D from Step 3]
Root Cause:
[One paragraph explaining the mismatch]
Recommended Fix:
[Specific action — upgrade model / decompose queries / fix retrieval / compress context]
Estimated Impact:
[Quality improvement expected] / [Cost change expected]
Related Skills:
[Link to diagnosing-rag-failure-modes / designing-hybrid-context-layers as applicable]