diff --git a/harness/.pi/extensions/gate/__tests__/gate_disambiguation_clarification.test.js b/harness/.pi/extensions/gate/__tests__/gate_disambiguation_clarification.test.js
new file mode 100644
index 00000000..c2fe0740
--- /dev/null
+++ b/harness/.pi/extensions/gate/__tests__/gate_disambiguation_clarification.test.js
@@ -0,0 +1,203 @@
+const test = require("node:test");
+const assert = require("node:assert");
+const { createDisambiguationGate } = require("../disambiguation/index.js");
+
+
+function setupClarification({
+  phase = 1,
+  knownTypes = new Set(["concept_clarified", "ambiguity_open", "value_grounded"]),
+  minimumPhases = {
+    concept_clarified: 1,
+    ambiguity_open: 1,
+    value_grounded: 3,
+  },
+} = {}) {
+  const calls = [];
+  const gate = createDisambiguationGate({
+    workflow: {
+      phase: (_ctx, session) => {
+        calls.push(["phase", session]);
+        return { number: phase };
+      },
+      describe: (_ctx, session) => {
+        calls.push(["describe", session]);
+        return "F1";
+      },
+      decisionTypes: () => {
+        calls.push(["decisionTypes"]);
+        return knownTypes;
+      },
+      decisionMinimumPhases: () => {
+        calls.push(["decisionMinimumPhases"]);
+        return minimumPhases;
+      },
+      advance: () => ({ advanced: false }),
+    },
+    session: { mutate: () => null },
+    ledger: {
+      record: () => null,
+    },
+    reviewer: {
+      buildSelect: (input) => {
+        calls.push(["build", input]);
+        return { type: "ui_request", widget: "select", ...input };
+      },
+      isReserved: (label) => ["Altro", "Other"].includes(label),
+    },
+    toTextResult: (text) => ({ content: [{ type: "text", text }] }),
+  });
+  return { gate, calls };
+}
+
+
+const OPTIONS = [
+  {
+    id: "procedure",
+    label: "Procedura clinica",
+    recommended: true,
+    decision: {
+      type: "concept_clarified",
+      subject: "ablazione",
+      detail: "procedura clinica",
+      rationale: "scelta dal reviewer",
+    },
+  },
+  { id: "ask", label: "Serve un altro chiarimento" },
+  { id: "other", label: "Altro" },
+];
+
+
+test("Disambiguation normalizes stringified F1 options", () => {
+  const { gate } = setupClarification();
+
+  assert.deepEqual(
+    gate.prepareClarificationArguments({ session: "s1", options: JSON.stringify(OPTIONS) }),
+    { session: "s1", options: OPTIONS },
+  );
+  assert.deepEqual(
+    gate.prepareClarificationArguments({ session: "s1", options: "not-json" }),
+    { session: "s1", options: "not-json" },
+  );
+});
+
+
+test("Disambiguation validates and presents F1 clarification options", () => {
+  const { gate, calls } = setupClarification();
+
+  const prepared = gate.prepareClarification({}, {
+    session: "s1",
+    title: "Che cosa significa ablazione?",
+    intro: "Una sola interpretazione può essere corretta.",
+    options: OPTIONS,
+    advance: true,
+  }, "u1");
+
+  assert.deepEqual(calls.map(([kind]) => kind), [
+    "decisionTypes", "phase", "decisionMinimumPhases", "describe", "build",
+  ]);
+  assert.deepEqual(prepared, {
+    session: "s1",
+    options: OPTIONS,
+    advance: true,
+    widget: {
+      type: "ui_request",
+      widget: "select",
+      id: "u1",
+      phase: "F1",
+      title: "Che cosa significa ablazione?",
+      intro: "Una sola interpretazione può essere corretta.",
+      recommended: "procedure",
+      options: [
+        { id: "procedure", label: "Procedura clinica" },
+        { id: "ask", label: "Serve un altro chiarimento" },
+      ],
+    },
+  });
+});
+
+
+test("Disambiguation rejects an unknown F1 decision type before presentation", () => {
+  const { gate, calls } = setupClarification();
+  const invalidOptions = [{
+    id: "invalid",
+    label: "Invalida",
+    decision: { type: "not_a_decision", subject: "x" },
+  }];
+
+  const prepared = gate.prepareClarification({}, {
+    session: "s1",
+    title: "Domanda",
+    options: invalidOptions,
+  }, "u1");
+
+  assert.deepEqual(calls.map(([kind]) => kind), ["decisionTypes"]);
+  assert.equal(
+    prepared.result.content[0].text,
+    "Tipo di decisione 'not_a_decision' non valido. Tipi ammessi: " +
+      "concept_clarified, ambiguity_open, value_grounded. Correggi e riprova.",
+  );
+});
+
+
+test("Disambiguation rejects a decision that belongs to a later phase", () => {
+  const { gate, calls } = setupClarification();
+  const futureOptions = [{
+    id: "grounded",
+    label: "Valore verificato",
+    decision: { type: "value_grounded", subject: "stato" },
+  }];
+
+  const prepared = gate.prepareClarification({}, {
+    session: "s1",
+    title: "Domanda",
+    options: futureOptions,
+  }, "u1");
+
+  assert.deepEqual(calls.map(([kind]) => kind), [
+    "decisionTypes", "phase", "decisionMinimumPhases",
+  ]);
+  assert.equal(
+    prepared.result.content[0].text,
+    "Tipo 'value_grounded' ammesso dalla Fase 3, sessione alla Fase 1. " +
+      "Chiudi prima la fase corrente.",
+  );
+});
+
+
+test("Disambiguation translates F1 choices into domain decisions or clarification requests", () => {
+  const { gate } = setupClarification();
+  const prepared = { options: OPTIONS };
+
+  const decision = gate.resolveClarification(prepared, { choices: ["procedure"] });
+  assert.deepEqual(decision.decision, OPTIONS[0].decision);
+  assert.match(decision.text, /Decisione registrata \(concept_clarified\): Procedura clinica\./);
+  assert.match(decision.text, /tht session show/);
+
+  assert.deepEqual(
+    gate.resolveClarification(prepared, { choices: ["ask"] }),
+    { text: "Scelta del reviewer: Serve un altro chiarimento" },
+  );
+  assert.deepEqual(
+    gate.resolveClarification(prepared, { choices: ["missing"] }),
+    { text: "Scelta del reviewer: missing" },
+  );
+});
+
+
+test("Disambiguation never translates F1 control responses into decisions", () => {
+  const { gate } = setupClarification();
+  const prepared = { options: OPTIONS };
+
+  assert.deepEqual(
+    gate.resolveClarification(prepared, { control: "freetext", text: "un altro significato" }),
+    { text: "Altro (reviewer): un altro significato" },
+  );
+  assert.deepEqual(
+    gate.resolveClarification(prepared, { control: "back" }),
+    { text: "Il reviewer vuole tornare indietro." },
+  );
+  assert.deepEqual(
+    gate.resolveClarification(prepared, { control: "exit" }),
+    { text: "Il reviewer vuole uscire." },
+  );
+});
diff --git a/harness/.pi/extensions/gate/disambiguation/index.js b/harness/.pi/extensions/gate/disambiguation/index.js
index f201f523..bed430b5 100644
--- a/harness/.pi/extensions/gate/disambiguation/index.js
+++ b/harness/.pi/extensions/gate/disambiguation/index.js
@@ -14,6 +14,108 @@ function normalizedAssumptions(assumptions) {
 }
 
 
+function prepareClarificationArguments(input) {
+	if (!input || typeof input !== "object") return input;
+	const args = { ...input };
+	if (typeof args.options === "string") {
+		try {
+			const parsed = JSON.parse(args.options);
+			if (Array.isArray(parsed)) args.options = parsed;
+		} catch {
+			// Preserve non-JSON input for the TypeBox/tool validation path.
+		}
+	}
+	return args;
+}
+
+
+function decisionRecordedText(decision, option) {
+	return (
+		`Decisione registrata (${decision.type}): ${option.label}. ` +
+		"Ora rileggi lo stato persistito con `tht session show` e invoca immediatamente " +
+		"il prossimo tool reviewer_ richiesto dal workflow. " +
+		"Non scrivere analisi o spiegazioni visibili."
+	);
+}
+
+
+function validateClarificationOptions(ctx, options, session, workflow) {
+	const known = workflow.decisionTypes(ctx);
+	if (!known) return null;
+	for (const option of options) {
+		if (option.decision && !known.has(option.decision.type)) {
+			return (
+				`Tipo di decisione '${option.decision.type}' non valido. Tipi ammessi: ` +
+				`${[...known].join(", ")}. Correggi e riprova.`
+			);
+		}
+	}
+	const current = workflow.phase(ctx, session).number;
+	const minimumPhases = workflow.decisionMinimumPhases(ctx);
+	for (const option of options) {
+		const type = option.decision?.type;
+		if (type && minimumPhases[type] && minimumPhases[type] > current) {
+			return (
+				`Tipo '${type}' ammesso dalla Fase ${minimumPhases[type]}, ` +
+				`sessione alla Fase ${current}. Chiudi prima la fase corrente.`
+			);
+		}
+	}
+	return null;
+}
+
+
+function prepareClarification(
+	ctx,
+	params,
+	id,
+	{ workflow, reviewer, toTextResult },
+) {
+	const { session, title, options, intro, advance } = params;
+	const validationError = validateClarificationOptions(ctx, options, session, workflow);
+	if (validationError) return { result: toTextResult(validationError) };
+	const phase = workflow.describe(ctx, session);
+	const recommended = options.find((option) => option.recommended)?.id ?? null;
+	return {
+		session,
+		options,
+		advance,
+		widget: reviewer.buildSelect({
+			id,
+			phase,
+			title,
+			intro: intro ?? null,
+			recommended,
+			options: options
+				.filter((option) => !reviewer.isReserved(option.label))
+				.map((option) => ({ id: option.id, label: option.label })),
+		}),
+	};
+}
+
+
+function resolveClarification(prepared, response) {
+	if (response?.control === "freetext") {
+		return { text: `Altro (reviewer): ${response.text}` };
+	}
+	if (response?.control === "back") {
+		return { text: "Il reviewer vuole tornare indietro." };
+	}
+	if (response?.control === "exit") {
+		return { text: "Il reviewer vuole uscire." };
+	}
+	const choice = Array.isArray(response?.choices) ? response.choices[0] : response?.choice;
+	const option = (prepared.options || []).find((candidate) => candidate.id === choice) || null;
+	if (option?.decision) {
+		return {
+			decision: option.decision,
+			text: decisionRecordedText(option.decision, option),
+		};
+	}
+	return { text: `Scelta del reviewer: ${option ? option.label : choice}` };
+}
+
+
 function installDisambiguationGate(
 	pi,
 	{ workflow, session, ledger, toTextResult },
@@ -73,5 +175,9 @@ function installDisambiguationGate(
 export function createDisambiguationGate(dependencies) {
 	return {
 		install: (pi) => installDisambiguationGate(pi, dependencies),
+		prepareClarificationArguments,
+		prepareClarification: (ctx, params, id) =>
+			prepareClarification(ctx, params, id, dependencies),
+		resolveClarification,
 	};
 }
diff --git a/harness/.pi/extensions/tht-gate.js b/harness/.pi/extensions/tht-gate.js
index 7ae09ec8..b3ec142e 100644
--- a/harness/.pi/extensions/tht-gate.js
+++ b/harness/.pi/extensions/tht-gate.js
@@ -626,6 +626,9 @@ export default function (pi) {
 				lockActive = true;
 			},
 			phase: (ctx, session) => ({ number: currentPhase(ctx, session) }),
+			describe: (ctx, session) => phaseId(ctx, currentPhase(ctx, session)),
+			decisionTypes: knownDecisionTypes,
+			decisionMinimumPhases: decisionMinPhaseMap,
 			advance: advancePhaseAndFinalize,
 		},
 		session: {
@@ -638,6 +641,10 @@ export default function (pi) {
 				ctx, decisionAddArgs(session, decision), recovery,
 			),
 		},
+		reviewer: {
+			buildSelect: buildSelectRequest,
+			isReserved,
+		},
 		toTextResult: textResult,
 	});
 
@@ -828,49 +835,26 @@ export default function (pi) {
 			intro: Type.Optional(Type.String()),
 			advance: Type.Optional(Type.Boolean()),
 		}),
-		prepareArguments: prepareReviewerArguments,
+		prepareArguments: disambiguationGate.prepareClarificationArguments,
 		async execute(_id, params, _signal, _onUpdate, ctx) {
 			lockActive = true;
 			try {
-			const { session, title, options: opts, intro, advance } = params;
-			const typeErr = validateDecisionTypes(ctx, opts, session);
-			if (typeErr) return textResult(typeErr);
-			const phase = phaseId(ctx, currentPhase(ctx, session));
-			const recommended = opts.find((o) => o.recommended)?.id ?? null;
-
-			const widget = buildSelectRequest({
-				id: `u${Date.now()}`,
-				phase,
-				title,
-				intro: intro ?? null,
-				recommended,
-				options: opts
-					.filter((o) => !isReserved(o.label))
-					.map((o) => ({ id: o.id, label: o.label })),
-			});
-			const resp = await emitAndWait(ctx, widget);
-			const outcome = resolveSelectOutcome(opts, resp);
-			if (outcome.kind === "freetext")
-				return textResult(`Altro (reviewer): ${outcome.text}`);
-			if (outcome.kind === "back")
-				return textResult("Il reviewer vuole tornare indietro.");
-			if (outcome.kind === "exit")
-				return textResult("Il reviewer vuole uscire.");
-			if (outcome.kind === "decision") {
+			const prepared = disambiguationGate.prepareClarification(
+				ctx, params, `u${Date.now()}`,
+			);
+			if (prepared.result) return prepared.result;
+			const response = await emitAndWait(ctx, prepared.widget);
+			const outcome = disambiguationGate.resolveClarification(prepared, response);
+			if (outcome.decision) {
 				const err = relayIfThtFails(
 					ctx,
-					decisionAddArgs(session, outcome.decision),
+					decisionAddArgs(prepared.session, outcome.decision),
 					"",
 				);
 				if (err) return err;
-				if (advance) advanceIfReady(ctx, session);
-				return textResult(
-					decisionRecordedResultText(outcome.decision, outcome.option),
-				);
+				if (prepared.advance) advanceIfReady(ctx, prepared.session);
 			}
-			return textResult(
-				`Scelta del reviewer: ${outcome.option ? outcome.option.label : outcome.choice}`,
-			);
+			return textResult(outcome.text);
 			} catch (fatal) {
 				const msg = (fatal.stderr || fatal.message || String(fatal)).toString().trim();
 				return textResult(`[reviewer_select ERRORE INTERNO] ${msg}. Riprova o usa un approccio diverso.`);