Generate Bounds

Generate Bounds for Extracted Parameters

Overview

Wraps the bounds-estimator system prompt at system-prompt.txt (next to this file) and applies it to a parameter JSON produced by extract-parameters-from-full (and ideally already passed validate-parameters). Output is a strict JSON object keyed by variable id, with low / base / high / unit / rationale / source for every variable that needs an assumption range.

Stage 4 of the pipeline described in planexe_simulator/README.md.

When to Use

• User asks to "generate bounds", "estimate ranges", "add low/base/high", or "prepare for scenarios" given an extract-parameters-from-full JSON
• User wants to fill in assumptions for missing_values_to_estimate and uncertain key_values before running deterministic scenarios or Monte Carlo
• Pipeline step between validate-parameters (passes clean) and generate-calculations / run-scenarios

Not for: regenerating the parameter JSON (use extract-parameters-from-full), validating the JSON (use validate-parameters), or producing Python code (use generate-calculations).

Workflow

1. Get the input JSON path. If the user did not provide one, ask. Do not guess.
2. Read system-prompt.txt (sibling of this SKILL.md). Its selection rules and spread heuristics are authoritative.
3. Read the parameter JSON. Assume it has already passed validate-parameters; if it visibly hasn't, tell the user and offer to validate first.
4. Produce the bounds JSON per the system prompt.
5. Self-audit before output. For each bound entry, verify:
   • Every numbered citation in rationale (Risk N, Issue N, Decision N) refers to content that substantively supports the claim — not just lexically present.
   • For variables feeding a declared gate threshold, the base-vs-threshold relationship is consistent with the rationale. If base implies base-case gate failure, the rationale names a report-internal anchor that justifies the shift.
   • source: "data" entries name an explicit anchor in the rationale.
   • For asymmetric bounds, the rationale notes the asymmetry's source. If any check fails, revise the bound; do not ship inconsistent state.
6. Output destination. Default: print the JSON to chat. If the user asks for a file, write to the path they specify. Suggested default file path: <input-basename>.bounds.json next to the input.

Selection Rules (re-stated for emphasis — see system prompt for full detail)

Generate one bounds entry for every id that meets ANY of:

• it appears in missing_values_to_estimate
• it is a key_value with value_type ∈ {inferred, missing_but_needed}
• it is a key_value with value == null
• it is a key_value with uncertainty == high
• it is a key_value with uncertainty == medium AND modelling_priority ∈ {critical, high}

Skip: explicit/derived key_values with low uncertainty, derived_questions, recommended_first_calculations, and formula LHS-only outputs that are not declared as inputs.

Spread by Uncertainty

Always low ≤ base ≤ high. Fractions stay in [0, 1]. Counts of discrete things (people, kits, centers, months) use integer bounds.

Output Shape

{
  "<variable_id>": {
    "unit": "fraction",
    "low": 0.10,
    "base": 0.20,
    "high": 0.30,
    "rationale": "Short, ≤50 words. Include required disclosures when applicable.",
    "source": "data" | "assumption",
    "sampling_discipline": "fraction",
    "non_negative": true,
    "default_pass_probability": null
  }
}

Top-level is a single object keyed by variable id. Order keys roughly by importance (critical → high → medium → remaining missing values). Use "source": "data" only when the range is anchored in a citable real-world reference for similar programs; otherwise "assumption".

Sampling-discipline tag

Each entry MUST carry a sampling_discipline chosen by the LLM based on the variable's nature. Downstream consumers (run-scenarios, monte-carlo runner) read this tag directly and do not pattern-match on unit strings — so the LLM is the single authority for this classification.

non_negative is independent of discipline: set true when the variable cannot legitimately go below zero (continuous monetary amounts, counts, capacities); set false only when negative values are physically meaningful (a delta or net change variable).

default_pass_probability is required (a number in [0, 1]) when sampling_discipline == "bernoulli_gate" and MUST be null for every other discipline.

If no variable needs bounds, return {}.

Common Mistakes

Reference

• System prompt (authoritative): system-prompt.txt
• Pipeline overview and "what needs bounds" list: ../../README.md, Stage 4
• Companion skills: ../extract-parameters-from-full/SKILL.md, ../validate-parameters/SKILL.md
• Example input for testing: /tmp/extract-params-heatwave-v8.json (passes validate-parameters with valid: true)