Deterministic Tool Registry

Tool	Owns	Fails closed when
validateChemicalEquation	species, phase, coefficients, balance	species or equation is outside frozen content
evaluateExpression	symbolic/numeric evaluation	variables or operations are unsupported
checkExpressionEquivalence	bounded AST equivalence	equivalence cannot be proven deterministically
convertUnit	dimensional conversion	dimensions conflict
validateMoleFractions	total moles, fractions, sum-to-one	species set or dependency is incomplete
validatePartialPressures	mole fraction × total pressure	total pressure/unit is missing
checkDependencyConsistency	use of upstream values	lineage is absent or ambiguous
checkSignificantFigures	required precision	policy lacks a precision rule
allocateMarks	named mark-node awards	policy/problem versions mismatch
applyBoundedECF	declared downstream credit	no exact ECF rule matches
verifyTrace	calls, provenance, invariant coverage	any authoritative claim lacks evidence

Tools accept and return typed objects with stable reason codes. No tool performs open-web retrieval or invents content. The orchestrator selects tools but cannot override them.