A state signing a human rights treaty is reported as a change in that country's obligations. Whether anything becomes enforceable inside the country depends on several further steps.
Signature and ratification do different things
Signature usually indicates an intention to be bound and an undertaking not to act against the treaty's purpose. It is a political commitment more than a legal one.
Ratification is the binding act, and in most systems it requires approval from the legislature or another domestic body. The gap between signature and ratification can last many years.
States may also enter reservations, declaring that particular provisions will not apply to them. A treaty accepted with extensive reservations can impose considerably less than its text suggests.
Two traditions on incorporation
Some legal systems treat a ratified treaty as part of domestic law automatically, allowing courts to apply its provisions without further legislation.
Others treat international and domestic law as separate systems. A treaty binds the state externally but has no internal effect until the legislature passes an implementing statute.
Many countries sit between the two, incorporating some categories of treaty directly and requiring legislation for others. The classification determines whether an individual can rely on the text in court.
Implementing legislation shapes the actual right
Where legislation is required, the drafters decide how the treaty language is translated. Broad standards must be turned into definitions, procedures, remedies and time limits.
That translation is where scope is set. A statute may protect a narrower class of people, or provide weaker remedies, than the treaty appears to require.
Implementation also assigns responsibility to specific agencies and gives them powers and budgets. A right without an institution behind it is difficult to exercise in practice.
Supervision is mostly through reporting
Most treaties establish a committee that receives periodic reports from states and issues observations. These bodies examine evidence and publish findings, but they do not function as courts.
Civil society organisations frequently submit parallel reports contesting the official account. That exchange is often the main source of independent information about implementation.
Some treaties add an optional complaint procedure allowing individuals to petition after exhausting domestic remedies. States must accept that procedure separately, and many do not.
Enforcement works through indirect pressure
International bodies rarely have direct coercive power over a state. Findings work through publicity, diplomatic consequences, litigation at home and the arguments they supply to domestic advocates.
Regional courts in some parts of the world issue binding judgments with stronger compliance mechanisms, though even there implementation depends on national authorities acting.
Because ratification status, reservations and incorporation methods all vary by country and are periodically revised, the position for any particular right has to be established locally.