🧯 fix: Keep Faded Completed Tool Calls From Reading as Truncated

src/agents/__tests__/projection.test.ts

@@ -23,7 +23,7 @@ const branch = (perMessageChars: number, count: number): AIMessage[] => {
     messages.push(
       i % 2 === 0
         ? (new HumanMessage(content) as unknown as AIMessage)
-        : new AIMessage(content),
+        : new AIMessage(content)
     );
   }
   return messages;
@@ -123,7 +123,7 @@ describe('projectAgentContextUsage', () => {
       messages,
       tokenCounter: countByChars,
       fadingTier: {
-        v: 1,
+        v: 2,
         budgetTokens: 10_000,
         masked: true,
         latched: true,

src/messages/__tests__/truncationStability.test.ts

@@ -181,25 +181,33 @@ describe('fading ladder', () => {
   });
 
   it('validates and seeds persisted tiers', () => {
-    expect(isFadingTier({ v: 1, budgetTokens: 100, masked: true })).toBe(true);
-    expect(isFadingTier({ v: 2, budgetTokens: 100, masked: true })).toBe(false);
-    expect(isFadingTier({ v: 1, budgetTokens: 0, masked: true })).toBe(false);
-    expect(isFadingTier({ v: 1, budgetTokens: 100, masked: 'yes' })).toBe(
+    expect(isFadingTier({ v: 2, budgetTokens: 100, masked: true })).toBe(true);
+    /** Version 1 tiers could latch on reconstructed history widths; they re-derive. */
+    expect(isFadingTier({ v: 1, budgetTokens: 100, masked: true })).toBe(false);
+    expect(
+      seedFadingTier(100_000, { v: 1, budgetTokens: 6_250, masked: false })
+    ).toEqual({
+      v: 2,
+      budgetTokens: 100_000,
+      masked: false,
+    });
+    expect(isFadingTier({ v: 2, budgetTokens: 0, masked: true })).toBe(false);
+    expect(isFadingTier({ v: 2, budgetTokens: 100, masked: 'yes' })).toBe(
       false
     );
     expect(isFadingTier(null)).toBe(false);
     expect(
-      seedFadingTier(100_000, { v: 1, budgetTokens: 50_000, masked: true })
+      seedFadingTier(100_000, { v: 2, budgetTokens: 50_000, masked: true })
     ).toEqual({
-      v: 1,
+      v: 2,
       budgetTokens: 50_000,
       masked: true,
       latched: true,
     });
     expect(
-      seedFadingTier(100_000, { v: 1, budgetTokens: 150_000, masked: false })
+      seedFadingTier(100_000, { v: 2, budgetTokens: 150_000, masked: false })
     ).toEqual({
-      v: 1,
+      v: 2,
       budgetTokens: 100_000,
       masked: false,
       latched: true,
@@ -217,7 +225,7 @@ describe('fading ladder', () => {
     expect(tier).toEqual(createFadingTier(window));
     tier = resolveFadingTier(tier, window, { ...base, contextPressure: 0.86 });
     expect(tier).toEqual({
-      v: 1,
+      v: 2,
       budgetTokens: 50_000,
       masked: true,
       latched: true,
@@ -236,7 +244,7 @@ describe('fading ladder', () => {
 
   it('survives a mid-run budget correction and the return to the normal window', () => {
     const latched: FadingTier = {
-      v: 1,
+      v: 2,
       budgetTokens: 100_000,
       masked: true,
       latched: true,
@@ -258,14 +266,14 @@ describe('fading ladder', () => {
 
   it('keeps a restored tier informative after clamping to a smaller window', () => {
     const restored = seedFadingTier(30_000, {
-      v: 1,
+      v: 2,
       budgetTokens: 50_000,
       masked: false,
       latched: true,
     });
 
     expect(restored).toEqual({
-      v: 1,
+      v: 2,
       budgetTokens: 30_000,
       masked: false,
       latched: true,
@@ -301,7 +309,7 @@ describe('fading ladder', () => {
     );
 
     expect(tier).toEqual({
-      v: 1,
+      v: 2,
       budgetTokens: 50_000,
       masked: false,
       latched: true,
@@ -335,7 +343,7 @@ describe('fading ladder', () => {
   });
 
   it('masks consumed results to a fraction of the fresh cap with a floor', () => {
-    const masked: FadingTier = { v: 1, budgetTokens: 100_000, masked: true };
+    const masked: FadingTier = { v: 2, budgetTokens: 100_000, masked: true };
     const caps = resolveFadingCaps(masked);
     expect(caps.consumedChars).toBe(Math.floor(caps.resultChars * 0.1));
     expect(
@@ -494,7 +502,7 @@ describe('pruner keeps historical tool results byte-stable across turns', () =>
       indexTokenCountMap: countMap(messages),
       summarizationEnabled: false,
       fadingTier: {
-        v: 1,
+        v: 2,
         budgetTokens: 5000,
         masked: true,
         latched: true,
@@ -800,7 +808,7 @@ describe('pruner keeps historical tool results byte-stable across turns', () =>
 
   it('restores legacy function calls identically across model windows', () => {
     const tier: FadingTier = {
-      v: 1,
+      v: 2,
       budgetTokens: 25_000,
       masked: false,
       latched: true,
@@ -993,7 +1001,7 @@ describe('pruner keeps historical tool results byte-stable across turns', () =>
       summarizationEnabled: false,
       thinkingEnabled: true,
       fadingTier: {
-        v: 1,
+        v: 2,
         budgetTokens: 10_000,
         masked: false,
         latched: true,
@@ -1011,7 +1019,7 @@ describe('pruner keeps historical tool results byte-stable across turns', () =>
     ]);
     expect(projected.additional_kwargs.reasoning_content).toBeUndefined();
     expect(JSON.stringify(projected.tool_calls?.[0].args)).toContain(
-      '_truncated'
+      '_inputPrefix'
     );
     expect(canonicalMessages[1].content).toBe('');
     expect(
@@ -1135,9 +1143,9 @@ describe('isInformativeFadingTier', () => {
       }
     );
 
-    expect(
-      hasNonEmptyTextContent([accessorBlock, proxiedBlock] as never)
-    ).toBe(false);
+    expect(hasNonEmptyTextContent([accessorBlock, proxiedBlock] as never)).toBe(
+      false
+    );
     expect(hasNonEmptyTextContent(new Proxy([], {}) as never)).toBe(false);
   });
 
@@ -1148,19 +1156,19 @@ describe('isInformativeFadingTier', () => {
     );
     expect(
       isInformativeFadingTier(
-        { v: 1, budgetTokens: 100_000, masked: true },
+        { v: 2, budgetTokens: 100_000, masked: true },
         100_000
       )
     ).toBe(true);
     expect(
       isInformativeFadingTier(
-        { v: 1, budgetTokens: 50_000, masked: false },
+        { v: 2, budgetTokens: 50_000, masked: false },
         100_000
       )
     ).toBe(true);
     expect(
       isInformativeFadingTier(
-        { v: 1, budgetTokens: 50_000, masked: false },
+        { v: 2, budgetTokens: 50_000, masked: false },
         undefined
       )
     ).toBe(false);
@@ -1177,13 +1185,13 @@ describe('per-agent fading tier persistence', () => {
 
   it('restores keyed tiers without applying the default tier to every agent', () => {
     const defaultTier: FadingTier = {
-      v: 1,
+      v: 2,
       budgetTokens: 50_000,
       masked: false,
       latched: true,
     };
     const workerTier: FadingTier = {
-      v: 1,
+      v: 2,
       budgetTokens: 25_000,
       masked: true,
       latched: true,
@@ -1219,9 +1227,17 @@ describe('per-agent fading tier persistence', () => {
   it('ignores malformed restored tiers instead of reporting them back', () => {
     const graph = new StandardGraph({
       agents: [graphAgent('default'), graphAgent('worker')],
-      fadingTier: { v: 1, budgetTokens: Number.NaN, masked: true } as FadingTier,
+      fadingTier: {
+        v: 2,
+        budgetTokens: Number.NaN,
+        masked: true,
+      } as FadingTier,
       fadingTiers: {
-        worker: { v: 1, budgetTokens: 'abc', masked: true } as unknown as FadingTier,
+        worker: {
+          v: 2,
+          budgetTokens: 'abc',
+          masked: true,
+        } as unknown as FadingTier,
       },
     });
 
@@ -1233,7 +1249,7 @@ describe('per-agent fading tier persistence', () => {
 
   it('restores a tier learned after a persistent initial summary', () => {
     const postSummaryTier: FadingTier = {
-      v: 1,
+      v: 2,
       budgetTokens: 25_000,
       masked: true,
       latched: true,
@@ -1256,7 +1272,7 @@ describe('per-agent fading tier persistence', () => {
 
   it('round-trips prototype-sensitive agent IDs', () => {
     const tier: FadingTier = {
-      v: 1,
+      v: 2,
       budgetTokens: 25_000,
       masked: true,
       latched: true,
@@ -1282,31 +1298,46 @@ describe('seedFadingTier provenance', () => {
   });
 
   it('latches a seed that was tightened, masked, already latched, or clamped', () => {
-    expect(seedFadingTier(200_000, { v: 1, budgetTokens: 50_000, masked: false })).toEqual({
-      v: 1,
+    expect(
+      seedFadingTier(200_000, { v: 2, budgetTokens: 50_000, masked: false })
+    ).toEqual({
+      v: 2,
       budgetTokens: 50_000,
       masked: false,
       latched: true,
     });
-    expect(seedFadingTier(200_000, { v: 1, budgetTokens: 200_000, masked: true })).toEqual({
-      v: 1,
+    expect(
+      seedFadingTier(200_000, { v: 2, budgetTokens: 200_000, masked: true })
+    ).toEqual({
+      v: 2,
       budgetTokens: 200_000,
       masked: true,
       latched: true,
     });
     expect(
-      seedFadingTier(200_000, { v: 1, budgetTokens: 200_000, masked: false, latched: true })
-    ).toEqual({ v: 1, budgetTokens: 200_000, masked: false, latched: true });
-    expect(seedFadingTier(8_000, { v: 1, budgetTokens: 200_000, masked: false })).toEqual({
-      v: 1,
+      seedFadingTier(200_000, {
+        v: 2,
+        budgetTokens: 200_000,
+        masked: false,
+        latched: true,
+      })
+    ).toEqual({ v: 2, budgetTokens: 200_000, masked: false, latched: true });
+    expect(
+      seedFadingTier(8_000, { v: 2, budgetTokens: 200_000, masked: false })
+    ).toEqual({
+      v: 2,
       budgetTokens: 8_000,
       masked: false,
       latched: true,
     });
   });
 
   it('clamps a sub-floor budget up to the ladder floor so caps stay positive', () => {
-    const seeded = seedFadingTier(200_000, { v: 1, budgetTokens: 1, masked: false });
+    const seeded = seedFadingTier(200_000, {
+      v: 2,
+      budgetTokens: 1,
+      masked: false,
+    });
     expect(seeded.budgetTokens).toBe(FADING_MIN_BUDGET_TOKENS);
     expect(seeded.latched).toBe(true);
     expect(resolveFadingCaps(seeded).resultChars).toBeGreaterThan(0);
@@ -1318,7 +1349,10 @@ describe('fadingRungForExchangeChars', () => {
   it('deepens until a result plus its input fit, even when the result cap is tiny', () => {
     const window = 200_000;
     const target = 8_000;
-    const exchangeChars = (rung: number, maxToolResultChars?: number): number => {
+    const exchangeChars = (
+      rung: number,
+      maxToolResultChars?: number
+    ): number => {
       const budget = fadingBudgetTokens(window, rung);
       const resultChars = calculateMaxToolResultChars(budget);
       return (
@@ -1376,7 +1410,10 @@ describe('hasNonEmptyTextContent hostile iteration', () => {
       false
     );
     expect(
-      hasNonEmptyTextContent({ type: 'text', text: 'x' } as unknown as BaseMessage['content'])
+      hasNonEmptyTextContent({
+        type: 'text',
+        text: 'x',
+      } as unknown as BaseMessage['content'])
     ).toBe(false);
   });
 });

src/messages/__tests__/unicodeTruncation.test.ts

@@ -104,18 +104,30 @@ describe('Unicode-safe tool truncation', () => {
     for (let cap = 4; cap <= 200; cap++) {
       const serialized = serializeToolCallInput(input, cap);
       const projected = JSON.parse(serialized) as {
-        _truncated?: string;
+        _inputPrefix?: string;
         _originalChars?: number;
       };
       expect(serialized.length).toBeLessThanOrEqual(cap);
-      expect(projected._truncated?.isWellFormed() ?? true).toBe(true);
+      expect(projected._inputPrefix?.isWellFormed() ?? true).toBe(true);
       expect(serializeToolCallInput(projected, cap)).toBe(serialized);
-      if (projected._truncated != null) {
+      if (projected._inputPrefix != null) {
         expect(projected._originalChars).toBe(JSON.stringify(input).length);
       }
     }
   });
 
+  it('rewrites a legacy custom-tool input marker even when it fits', () => {
+    const message = customToolMessage(
+      'run --report\n… [truncated: 5400 chars]'
+    );
+
+    const projected = projectToolCallInputs([message], 1_000);
+
+    expect(customToolInput(projected[0])).toBe(
+      'run --report\n… [shortened; call completed: 5400 chars]'
+    );
+  });
+
   it('keeps custom-tool input marker and markerless cuts well-formed without mutating history', () => {
     const message = customToolMessage(emojiText);
     for (let cap = 4; cap <= 100; cap++) {
@@ -124,7 +136,9 @@ describe('Unicode-safe tool truncation', () => {
       expect(input.isWellFormed()).toBe(true);
       expect(input.length).toBeLessThanOrEqual(cap);
       if (cap > 50) {
-        expect(input).toContain(`\n… [truncated: ${emojiText.length} chars]`);
+        expect(input).toContain(
+          `\n… [shortened; call completed: ${emojiText.length} chars]`
+        );
         const shrunk = projectToolCallInputs(projected, 50);
         const direct = projectToolCallInputs([message], 50);
         expect(customToolInput(shrunk[0])).toBe(customToolInput(direct[0]));