Motivation

HTMA Measure helps an agent estimate a range that can support a decision. It records the evidence, assumptions, confidence, and conditions for stopping research.

An estimate needs evidence for its bounds and enough detail for someone to revise it when new information arrives.

The problem

Two common approaches fail in opposite ways:

• A quick point estimate is cheap but hides the uncertainty that controls the decision.
• Open-ended research collects more facts but often lacks a threshold, source hierarchy, or stopping rule.

Neither approach necessarily helps someone choose an action. Simulation can compound the problem by making weak assumptions look precise.

The mental model

Measurement is valuable when it changes a decision. The workflow therefore begins with the decision and target quantity, uses a threshold when one is available, decomposes uncertainty, and buys information only where it can change the action.

The range should reflect what the evidence can support.

Key design decisions

• Decision context before research. Identify the target and use its threshold when available. Clarify ambiguity that prevents a responsible estimate; a missing threshold alone need not block a useful range.
• Ranges before simulation. Establish defensible input ranges before running Monte Carlo. Simulation cannot justify weak inputs.
• Sources in the memo. Label facts, assumptions, and inference. This adds length but lets the reader check the estimate.
• Prose and JSON together. Explain the estimate in prose and provide JSON for reuse. Keep the two consistent.
• Missing inputs stay missing. When evidence cannot support a range, return null numeric fields and explain the blocker.

Alternatives considered

• A single reusable prompt. Too easy for an agent to skip thresholds, source grading, or verification.
• A calculator-only tool. Reliable arithmetic, but no judgment about target mode, evidence quality, or decision relevance.
• A simulation-first workflow. Precise output cannot rescue uncalibrated inputs.
• A full HTMA suite as a hard dependency. Requiring companion skills would limit where this skill works. They remain optional.

Non-goals

HTMA Measure is not:

• a guarantee that uncertain forecasts become accurate;
• a replacement for authoritative current data;
• a license to infer private financial facts;
• a full statistical software package; or
• a substitute for reviewing sources and assumptions.