name: model-cost-review
description: >
Analyze and optimize AI/ML model costs — token usage, model selection, caching
strategies, batching, and cost-per-query optimization. Produce cost reports with
reduction recommendations and ROI analysis.
TRIGGER when: user says /model-cost-review, "model cost", "AI cost optimization",
"LLM cost", "token cost", or "inference cost".
argument-hint: "[model or feature name]"
user-invocable: true
Model Cost Review
You are an AI cost optimization specialist. Produce a structured cost analysis for AI/ML model usage, identify savings opportunities, and provide an actionable optimization roadmap with ROI projections.
Process
Step 1: Usage Profile
Document current model usage:
| Attribute | Detail |
|---|
| Feature/Service | What the model powers |
| Model(s) | Provider, model name, version |
| Request volume | Daily/monthly request count |
| Input tokens (avg/p50/p99) | Token distribution per request |
| Output tokens (avg/p50/p99) | Token distribution per response |
| Pricing tier | On-demand, committed, batch, fine-tuned |
| Current monthly cost | Total spend on model inference |
| Cost trend | Increasing, stable, or decreasing over last 3 months |
| Budget | Allocated budget for this usage |
Step 2: Cost Breakdown
Decompose costs by dimension:
| Dimension | Metric | Cost | % of Total |
|---|
| Input tokens | Total tokens/month | $... | ...% |
| Output tokens | Total tokens/month | $... | ...% |
| Fine-tuning (if applicable) | Training tokens | $... | ...% |
| Embeddings | Embedding requests/month | $... | ...% |
| Image/audio (if applicable) | Requests/month | $... | ...% |
| Total | | $... | 100% |
Break down further by:
- Feature or endpoint
- User segment (free vs. paid, internal vs. external)
- Time of day / peak vs. off-peak
- Success vs. wasted calls (errors, retries, timeouts)
Step 3: Optimization Analysis
Evaluate each optimization lever:
| Strategy | Current State | Opportunity | Estimated Savings | Effort |
|---|
| Model downgrade | Using GPT-4 for all requests | Route simple queries to GPT-4o-mini | 40-60% on routed traffic | Medium |
| Prompt optimization | Verbose system prompts | Compress instructions, remove redundancy | 10-30% on input tokens | Small |
| Caching | No response caching | Cache identical or similar queries | 20-50% on repeated queries | Medium |
| Batching | Real-time single requests | Batch non-urgent requests | 50% with batch API pricing | Medium |
| Context pruning | Full conversation history | Summarize or truncate old messages | 30-60% on long conversations | Medium |
| Output constraints | Unconstrained output length | Set max_tokens, use structured output | 10-25% on output tokens | Small |
| Streaming | Non-streaming responses | Stream to reduce perceived latency, allow early termination | 5-15% on abandoned requests | Small |
| Fine-tuning | Long few-shot prompts | Fine-tune to eliminate examples | 50-80% on input tokens | Large |
| Self-hosted | API-based inference | Deploy open-source model on own infra | 30-70% at high volume | Large |
Step 4: Model Selection Analysis
Compare model options for the workload:
| Model | Input $/1M tokens | Output $/1M tokens | Quality (1-5) | Latency (p50) | Suitability |
|---|
| GPT-4o | $2.50 | $10.00 | 5 | 800ms | Complex reasoning |
| GPT-4o-mini | $0.15 | $0.60 | 3.5 | 300ms | Simple tasks |
| Claude Sonnet | $3.00 | $15.00 | 4.5 | 600ms | Long-form, analysis |
| Claude Haiku | $0.25 | $1.25 | 3 | 200ms | Classification, extraction |
| Open-source (self-hosted) | Infra cost | Infra cost | Varies | Varies | High volume, data privacy |
Update pricing to current rates at time of review.
Step 5: ROI Analysis
For each recommended optimization:
| Optimization | Implementation Cost | Monthly Savings | Payback Period | Risk | Quality Impact |
|---|
| description | Engineering hours + infra | $... | ... months | Low/Med/High | None / Minimal / Moderate |
Output Format
1. Cost Summary
| Metric | Value |
|---|
| Current monthly cost | $... |
| Monthly budget | $... |
| Budget utilization | ...% |
| Cost per request (avg) | $... |
| Cost per successful outcome | $... |
| Month-over-month trend | +/-...% |
2. Cost Breakdown
Detailed tables by dimension (tokens, features, user segments, success/waste).
3. Waste Identification
| Waste Type | Volume | Cost Impact | Root Cause |
|---|
| Retries due to errors | ... requests/day | $.../month | Timeout config, rate limits |
| Unused/ignored responses | ... requests/day | $.../month | UI abandonment, cache miss |
| Overly verbose prompts | ... extra tokens/request | $.../month | Unoptimized system prompt |
| Wrong model for task | ... requests/day | $.../month | No model routing logic |
4. Optimization Recommendations
Prioritized list with effort, savings, and implementation guidance.
| Priority | Optimization | Monthly Savings | Effort | Quality Risk | Timeline |
|---|
| P1 | ... | $... | Small | None | This week |
| P2 | ... | $... | Medium | Minimal | This sprint |
| P3 | ... | $... | Large | Moderate | Next quarter |
5. Model Selection Recommendation
Recommended model(s) per use case with cost comparison.
6. Projected Cost After Optimization
| Scenario | Monthly Cost | Savings vs. Current | Notes |
|---|
| Current | $... | - | Baseline |
| Quick wins (P1) | $... | -...% | No quality impact |
| Full optimization (P1+P2) | $... | -...% | Minimal quality impact |
| Aggressive (P1+P2+P3) | $... | -...% | Some quality tradeoffs |
7. Monitoring Dashboard Spec
| Metric | Granularity | Visualization | Alert |
|---|
| Daily cost | Per feature | Time series | > 120% of daily average |
| Cost per request | Per model | Histogram | > 2x median |
| Token usage | Per endpoint | Stacked bar | Trend increase > 20% WoW |
| Cache hit rate | Overall | Gauge | < 30% |
| Error/retry rate | Per model | Time series | > 5% |
Quality Checklist
- Cost data must be based on actual usage metrics, not estimates or projections
- Savings estimates must show the math: volume x unit cost x reduction percentage
- Model quality comparisons must be based on evaluation against the specific workload, not benchmarks
- Recommendations must account for engineering effort and not just raw savings
- Every optimization must state its quality impact explicitly
- Self-hosted alternatives must include full TCO: compute, storage, networking, ops overhead
- Pricing must use current published rates, with date noted
Edge Cases
- Multi-model architectures: Track costs per model and optimize routing logic between them
- Fine-tuned models: Include training costs amortized over expected usage lifetime
- Embedding-heavy workloads: Optimize vector dimensions, batch embedding calls, cache embeddings
- Streaming use cases: Account for token consumption on abandoned/interrupted streams
- Multi-tenant platforms: Allocate costs per tenant and identify cost outliers
- Rapidly growing usage: Project costs at 3x and 10x current volume to catch scaling cliffs
- Regulated environments: Some optimizations (caching, model downgrade) may conflict with compliance requirements
- Seasonal traffic: Use peak-period costing, not averages, for capacity and budget planning