Thinking First Principles Agent Skill

First Principles

Strip assumed constraints to independently supported primitives, then rebuild. Escape analogy when convention fails or looks artificially expensive.

When to Use

• A constraint is treated as fixed ("too expensive," "impossible," "always done this way") without independent support.
• Convention or analogy has failed, stalled, or only yields weak incremental variants.
• Greenfield design where industry defaults may smuggle false requirements.
• Cost or feasibility claims rest on pricing, precedent, or authority rather than physics, math, or measured need.

When NOT to Use

• The constraint is verified physics, hard regulation, or measured capacity → accept it and optimize within it.
• A proven standard library, protocol, or known-good pattern already fits → use it; do not re-derive.
• Time-critical incidents → act on the most likely cause first; reserve first-principles rebuild for post-incident redesign.
• Incremental polish of a working system with no false-constraint signal → skip.

Procedure

• State the problem and claimed constraints. List every limit treated as fixed (cost, scale, stack, process, "must use X").
• Classify each constraint. Tag as physics/math, regulation/contract, measured fact, or convention/analogy/authority. Keep only the first three as binding unless evidence upgrades a convention.
• Decompose to primitives. Required inputs, conservation/complexity bounds, true non-negotiables. Demand independent support (measurement, derivation, primary requirement)—not vendor pricing or competitor precedent.
• Discard unsupported assumptions. For each convention tag, state a falsifier. Drop or renegotiate anything lacking support.
• Rebuild from remaining primitives only. Simplest solution that satisfies binding constraints and ignores artificial ones. Prefer commodity inputs and fewer moving parts over analogy.
• Validate and stop. Check against real physics, contracts, and measured needs. Define the cheapest kill test. Stop when a coherent rebuild plus discriminating validation exists, or when only verified hard constraints remain.

Output

Emit a first-principles rebuild:

• claimed_constraints: list with classification tags
• primitives: independently supported truths only
• discarded_assumptions: conventions dropped and why
• rebuild: solution derived only from primitives
• binding_residuals: real limits that remain
• kill_test: cheapest check that would falsify the rebuild

Verification

• Independence check: every primitive must cite measurement, derivation, or primary requirement—not precedent alone.
• No smuggled analogy: if the rebuild still depends on "how others do it" without a primitive, strip it.
• Constraint honesty: verified physics/regulation must remain; do not wish them away.
• Over-application guard: if a standard solution is already optimal under verified constraints, do not rebuild for novelty.
• Stop: one decompose → classify → rebuild → kill-test pass; do not recurse without new evidence.