Simulation sandbox
Test scenarios, decisions, and code without real-world consequences. Use for what-if analysis, prototyping, stress-testing, and war-gaming strategic decisions.From its SKILL.md
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SKILL.md
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Simulation Sandbox
Context
Activate this skill when the user needs to test a scenario, decision, or piece of code without real-world consequences. This includes:
- Evaluating architectural decisions before implementation
- Stress-testing business logic under hypothetical conditions
- Exploring "what-if" scenarios (market changes, load spikes, failure modes)
- Prototyping algorithms or data pipelines with synthetic data
- War-gaming strategic decisions (competitor moves, pricing changes)
- Testing code behavior with edge-case inputs
Do not use when the user needs real data analysis, wants to execute actual code in production, or requires factual reporting rather than speculative modeling.
Instructions
Step 1: Define the Simulation Scope
- What is being simulated (system, process, decision, code)
- Why it is being simulated (question to answer, risk to evaluate)
- Boundaries (what is in scope and out of scope)
- Key metrics (what success/failure looks like)
Step 2: Establish Parameters and Assumptions
- Input values (synthetic, estimated, or from user)
- Environmental conditions (load, time period, external factors)
- Assumptions that simplify the model (and their potential impact)
- Fixed variables vs. variables to be tested across ranges
Step 3: Build the Simulation Model
- Describe the initial state
- Define the rules/logic that govern each step
- Identify feedback loops or cascading effects
- Set the number of iterations or time steps
Step 4: Run Scenarios
- Baseline: Expected/normal conditions
- Best case: Optimistic but plausible inputs
- Worst case: Pessimistic but plausible inputs
- Edge cases: Boundary conditions, extreme values
- Stress test: Push parameters beyond normal range
Step 5: Observe and Record Outcomes
For each scenario capture:
- Key metric values at each time step
- Points of failure or unexpected behavior
- Patterns that emerge across scenarios
Step 6: Report Findings
- Executive summary (2–3 sentences)
- Scenario comparison
- Key findings and patterns
- Sensitivity analysis
- Limitations of the simulation
- Recommended next steps
Step 7: Label Everything
- All numbers prefaced with
[SIMULATED] - Frame as "In this simulation model..." or "Under these parameters..."
- Never present simulated data as empirical fact
Constraints
- Always label simulated outputs. Use
[SIMULATED]tags prominently. - State limitations explicitly. Every simulation has blind spots — name them.
- Use plausible parameters. Even stress tests should use values that could theoretically occur.
- Never claim predictive accuracy. Use language like "suggests," "indicates," "under these conditions."
- Separate signal from noise. Call out if a result is driven by a simplifying assumption.
- Complete the full cycle. Every simulation must include Steps 1–7.
Examples
Example 1: API Load Testing
User: "Will our API survive 10x traffic?"
Output:
═══ SIMULATION: API Load Capacity Test ═══
Step 1 — Scope
System: REST API, question: At what traffic does degradation begin?
Metrics: P50/P99 latency, error rate (%)
Step 2 — Parameters
- Baseline: 500 req/sec, P50=45ms, P99=120ms, error=0.1%
- [ASSUMPTION] Infrastructure scales vertically
Step 3 — Model
Each step = 1 second. Logic: req/sec → pool util → queue → latency.
Failure trigger: queue > 100 or error > 5%.
Step 4 — Scenarios
┌────────────┬────────┬─────────┬─────────┬─────────┐
│ Scenario │req/sec │P50(ms) │P99(ms) │Error Rate│
├────────────┼────────┼─────────┼─────────┼─────────┤
│ Baseline │ [SIM]500│[SIM]45 │[SIM]120 │[SIM]0.1%│
│ 3x load │ [SIM]1500│[SIM]62 │[SIM]210 │[SIM]0.3%│
│ 10x load │ [SIM]5000│[SIM]340│[SIM]2100│[SIM]8.7%│
└────────────┴────────┴─────────┴─────────┴─────────┘
Step 5 — Findings
[SIMULATED] Degradation begins between 3x–5x load.
Connection pool saturation is the primary bottleneck.
Step 6 — Recommendation
Horizontal scaling + connection pooling before 5x load.
═══ END SIMULATION ═══
What ships with it
Read from the repository
Just SKILL.md. No reference files, no scripts.
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Said here and by no other author read
- define the simulation scope
- establish parameters and assumptions
- build the simulation model
- run baseline, edge, and stress scenarios
- observe and record outcomes
- report findings and recommended next steps
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