diff --git a/apps/cli/src/commands/eval/artifact-writer.ts b/apps/cli/src/commands/eval/artifact-writer.ts
index 003d8886..755d36a1 100644
--- a/apps/cli/src/commands/eval/artifact-writer.ts
+++ b/apps/cli/src/commands/eval/artifact-writer.ts
@@ -15,7 +15,9 @@ export function buildTestTargetKey(testId?: string, target?: string): string {
 }
 
 // Deduplication helper — keeps the last entry per (test_id, target) pair.
-export function deduplicateByTestIdTarget(results: readonly EvaluationResult[]): EvaluationResult[] {
+export function deduplicateByTestIdTarget(
+  results: readonly EvaluationResult[],
+): EvaluationResult[] {
   const seen = new Map<string, number>();
   for (let i = 0; i < results.length; i++) {
     seen.set(buildTestTargetKey(results[i].testId, results[i].target), i);
diff --git a/apps/cli/src/commands/eval/run-eval.ts b/apps/cli/src/commands/eval/run-eval.ts
index b1737f19..a69078be 100644
--- a/apps/cli/src/commands/eval/run-eval.ts
+++ b/apps/cli/src/commands/eval/run-eval.ts
@@ -527,7 +527,7 @@ async function prepareFileMetadata(params: {
   readonly yamlWorkers?: number;
   readonly yamlCache?: boolean;
   readonly yamlCachePath?: string;
-  readonly totalBudgetUsd?: number;
+  readonly budgetUsd?: number;
   readonly failOnError?: FailOnError;
   readonly threshold?: number;
   readonly tags?: readonly string[];
@@ -654,7 +654,7 @@ async function prepareFileMetadata(params: {
     yamlWorkers: suite.workers,
     yamlCache: suite.cacheConfig?.enabled,
     yamlCachePath: suite.cacheConfig?.cachePath,
-    totalBudgetUsd: suite.totalBudgetUsd,
+    budgetUsd: suite.budgetUsd,
     failOnError: suite.failOnError,
     threshold: suite.threshold,
     tags: suite.metadata?.tags,
@@ -680,7 +680,7 @@ async function runSingleEvalFile(params: {
   readonly testCases: readonly EvalTest[];
   readonly trialsConfig?: TrialsConfig;
   readonly matrixMode?: boolean;
-  readonly totalBudgetUsd?: number;
+  readonly budgetUsd?: number;
   readonly failOnError?: FailOnError;
   readonly threshold?: number;
   readonly providerFactory?: (
@@ -706,7 +706,7 @@ async function runSingleEvalFile(params: {
     testCases,
     trialsConfig,
     matrixMode,
-    totalBudgetUsd,
+    budgetUsd,
     failOnError,
     providerFactory,
   } = params;
@@ -802,7 +802,7 @@ async function runSingleEvalFile(params: {
     workspacePath: options.workspacePath,
     keepWorkspaces: options.keepWorkspaces,
     trials: trialsConfig,
-    totalBudgetUsd,
+    budgetUsd,
     failOnError,
     graderTarget: options.graderTarget,
     model: options.model,
@@ -1166,7 +1166,7 @@ export async function runEvalCommand(
       readonly yamlWorkers?: number;
       readonly yamlCache?: boolean;
       readonly yamlCachePath?: string;
-      readonly totalBudgetUsd?: number;
+      readonly budgetUsd?: number;
       readonly failOnError?: FailOnError;
       readonly threshold?: number;
       readonly tags?: readonly string[];
@@ -1439,7 +1439,7 @@ export async function runEvalCommand(
               testCases: filteredTestCases,
               trialsConfig: options.transcript ? undefined : targetPrep.trialsConfig,
               matrixMode: targetPrep.selections.length > 1,
-              totalBudgetUsd: targetPrep.totalBudgetUsd,
+              budgetUsd: targetPrep.budgetUsd,
               failOnError: targetPrep.failOnError,
               threshold: resolvedThreshold,
               providerFactory: transcriptProviderFactory,
diff --git a/packages/core/src/evaluation/loaders/config-loader.ts b/packages/core/src/evaluation/loaders/config-loader.ts
index eeb68ac4..7aede85f 100644
--- a/packages/core/src/evaluation/loaders/config-loader.ts
+++ b/packages/core/src/evaluation/loaders/config-loader.ts
@@ -394,14 +394,22 @@ export function extractCacheConfig(suite: JsonObject): CacheConfig | undefined {
  * Extract suite-level total budget from parsed eval suite's execution block.
  * Returns undefined when not specified.
  */
-export function extractTotalBudgetUsd(suite: JsonObject): number | undefined {
+export function extractBudgetUsd(suite: JsonObject): number | undefined {
   const execution = suite.execution;
   if (!execution || typeof execution !== 'object' || Array.isArray(execution)) {
     return undefined;
   }
 
   const executionObj = execution as Record<string, unknown>;
-  const rawBudget = executionObj.total_budget_usd ?? executionObj.totalBudgetUsd;
+
+  // Reject the old key with a clear error
+  if ('total_budget_usd' in executionObj || 'totalBudgetUsd' in executionObj) {
+    throw new Error(
+      'execution.total_budget_usd has been renamed to execution.budget_usd. Update your eval YAML.',
+    );
+  }
+
+  const rawBudget = executionObj.budget_usd ?? executionObj.budgetUsd;
 
   if (rawBudget === undefined || rawBudget === null) {
     return undefined;
@@ -411,9 +419,7 @@ export function extractTotalBudgetUsd(suite: JsonObject): number | undefined {
     return rawBudget;
   }
 
-  logWarning(
-    `Invalid execution.total_budget_usd: ${rawBudget}. Must be a positive number. Ignoring.`,
-  );
+  logWarning(`Invalid execution.budget_usd: ${rawBudget}. Must be a positive number. Ignoring.`);
   return undefined;
 }
 
diff --git a/packages/core/src/evaluation/orchestrator.ts b/packages/core/src/evaluation/orchestrator.ts
index 2b77d604..6a1a3a0c 100644
--- a/packages/core/src/evaluation/orchestrator.ts
+++ b/packages/core/src/evaluation/orchestrator.ts
@@ -413,7 +413,7 @@ export interface RunEvaluationOptions {
   /** Real-time observability callbacks passed to the provider */
   readonly streamCallbacks?: ProviderStreamCallbacks;
   /** Suite-level total cost budget in USD (stops dispatching when exceeded) */
-  readonly totalBudgetUsd?: number;
+  readonly budgetUsd?: number;
   /** Execution error tolerance: true halts on first error */
   readonly failOnError?: FailOnError;
   /** Workspace pooling: true (default) enables pool, false disables, undefined defaults to true */
@@ -466,7 +466,7 @@ export async function runEvaluation(
     cleanupWorkspaces,
     trials,
     streamCallbacks,
-    totalBudgetUsd,
+    budgetUsd,
     failOnError,
     poolWorkspaces,
     poolMaxSlots: configPoolMaxSlots,
@@ -1162,7 +1162,7 @@ export async function runEvaluation(
       workerIdByEvalId.set(evalCase.id, workerId);
 
       // Check suite-level budget before dispatching
-      if (totalBudgetUsd !== undefined && budgetExhausted) {
+      if (budgetUsd !== undefined && budgetExhausted) {
         const budgetResult: EvaluationResult = {
           timestamp: (now ?? (() => new Date()))().toISOString(),
           testId: evalCase.id,
@@ -1172,13 +1172,13 @@ export async function runEvaluation(
           assertions: [],
           output: [],
           target: target.name,
-          error: `Suite budget exceeded ($${cumulativeBudgetCost.toFixed(4)} / $${totalBudgetUsd.toFixed(4)})`,
+          error: `Suite budget exceeded ($${cumulativeBudgetCost.toFixed(4)} / $${budgetUsd.toFixed(4)})`,
           budgetExceeded: true,
           executionStatus: 'execution_error',
           failureStage: 'setup',
           failureReasonCode: 'budget_exceeded',
           executionError: {
-            message: `Suite budget exceeded ($${cumulativeBudgetCost.toFixed(4)} / $${totalBudgetUsd.toFixed(4)})`,
+            message: `Suite budget exceeded ($${cumulativeBudgetCost.toFixed(4)} / $${budgetUsd.toFixed(4)})`,
             stage: 'setup',
           },
         };
@@ -1292,7 +1292,7 @@ export async function runEvaluation(
             : await runEvalCase(runCaseOptions);
 
         // Track suite-level budget
-        if (totalBudgetUsd !== undefined) {
+        if (budgetUsd !== undefined) {
           // Sum all trial costs when trials are used, otherwise use trace cost
           let caseCost: number | undefined;
           if (result.trials && result.trials.length > 0) {
@@ -1305,7 +1305,7 @@ export async function runEvaluation(
           }
           if (caseCost !== undefined) {
             cumulativeBudgetCost += caseCost;
-            if (cumulativeBudgetCost >= totalBudgetUsd) {
+            if (cumulativeBudgetCost >= budgetUsd) {
               budgetExhausted = true;
             }
           }
diff --git a/packages/core/src/evaluation/validation/eval-file.schema.ts b/packages/core/src/evaluation/validation/eval-file.schema.ts
index 4cb155d2..66946323 100644
--- a/packages/core/src/evaluation/validation/eval-file.schema.ts
+++ b/packages/core/src/evaluation/validation/eval-file.schema.ts
@@ -366,8 +366,8 @@ const ExecutionSchema = z.object({
   skip_defaults: z.boolean().optional(),
   cache: z.boolean().optional(),
   trials: TrialsSchema.optional(),
-  total_budget_usd: z.number().min(0).optional(),
-  totalBudgetUsd: z.number().min(0).optional(),
+  budget_usd: z.number().min(0).optional(),
+  budgetUsd: z.number().min(0).optional(),
   fail_on_error: FailOnErrorSchema.optional(),
   failOnError: FailOnErrorSchema.optional(),
   threshold: z.number().min(0).max(1).optional(),
diff --git a/packages/core/src/evaluation/yaml-parser.ts b/packages/core/src/evaluation/yaml-parser.ts
index 6b6c8f00..928e73d5 100644
--- a/packages/core/src/evaluation/yaml-parser.ts
+++ b/packages/core/src/evaluation/yaml-parser.ts
@@ -8,6 +8,7 @@ import { interpolateEnv } from './interpolation.js';
 import { loadTestsFromAgentSkills } from './loaders/agent-skills-parser.js';
 import { expandFileReferences, loadCasesFromFile } from './loaders/case-file-loader.js';
 import {
+  extractBudgetUsd,
   extractCacheConfig,
   extractFailOnError,
   extractTargetFromSuite,
@@ -15,7 +16,6 @@ import {
   extractTargetsFromSuite,
   extractTargetsFromTestCase,
   extractThreshold,
-  extractTotalBudgetUsd,
   extractTrialsConfig,
   extractWorkersFromSuite,
   loadConfig,
@@ -203,7 +203,7 @@ export type EvalSuiteResult = {
   /** Suite-level metadata (name, description, version, etc.) */
   readonly metadata?: import('./metadata.js').EvalMetadata;
   /** Suite-level total cost budget in USD */
-  readonly totalBudgetUsd?: number;
+  readonly budgetUsd?: number;
   /** Execution error tolerance: true or false */
   readonly failOnError?: import('./types.js').FailOnError;
   /** Suite-level quality threshold (0-1) — suite fails if mean score is below */
@@ -243,7 +243,7 @@ export async function loadTestSuite(
     targetRefs: extractTargetRefsFromSuite(parsed),
     workers: extractWorkersFromSuite(parsed),
     cacheConfig: extractCacheConfig(parsed),
-    totalBudgetUsd: extractTotalBudgetUsd(parsed),
+    budgetUsd: extractBudgetUsd(parsed),
     ...(metadata !== undefined && { metadata }),
     ...(failOnError !== undefined && { failOnError }),
     ...(threshold !== undefined && { threshold }),
diff --git a/packages/core/test/evaluation/loaders/config-loader.test.ts b/packages/core/test/evaluation/loaders/config-loader.test.ts
index 2c8ac2ad..303bf3a2 100644
--- a/packages/core/test/evaluation/loaders/config-loader.test.ts
+++ b/packages/core/test/evaluation/loaders/config-loader.test.ts
@@ -1,13 +1,13 @@
 import { describe, expect, it } from 'bun:test';
 
 import {
+  extractBudgetUsd,
   extractFailOnError,
   extractTargetFromSuite,
   extractTargetRefsFromSuite,
   extractTargetsFromSuite,
   extractTargetsFromTestCase,
   extractThreshold,
-  extractTotalBudgetUsd,
   extractTrialsConfig,
   parseExecutionDefaults,
   parseResultsConfig,
@@ -380,40 +380,54 @@ describe('extractTargetsFromTestCase', () => {
   });
 });
 
-describe('extractTotalBudgetUsd', () => {
+describe('extractBudgetUsd', () => {
   it('returns undefined when no execution block', () => {
     const suite: JsonObject = { tests: [] };
-    expect(extractTotalBudgetUsd(suite)).toBeUndefined();
+    expect(extractBudgetUsd(suite)).toBeUndefined();
   });
 
-  it('returns undefined when no total_budget_usd in execution', () => {
+  it('returns undefined when no budget_usd in execution', () => {
     const suite: JsonObject = { execution: { target: 'default' } };
-    expect(extractTotalBudgetUsd(suite)).toBeUndefined();
+    expect(extractBudgetUsd(suite)).toBeUndefined();
   });
 
-  it('parses valid total_budget_usd (snake_case)', () => {
-    const suite: JsonObject = { execution: { total_budget_usd: 10.0 } };
-    expect(extractTotalBudgetUsd(suite)).toBe(10.0);
+  it('parses valid budget_usd (snake_case)', () => {
+    const suite: JsonObject = { execution: { budget_usd: 10.0 } };
+    expect(extractBudgetUsd(suite)).toBe(10.0);
   });
 
-  it('parses valid totalBudgetUsd (camelCase)', () => {
-    const suite: JsonObject = { execution: { totalBudgetUsd: 5.5 } };
-    expect(extractTotalBudgetUsd(suite)).toBe(5.5);
+  it('parses valid budgetUsd (camelCase)', () => {
+    const suite: JsonObject = { execution: { budgetUsd: 5.5 } };
+    expect(extractBudgetUsd(suite)).toBe(5.5);
   });
 
   it('returns undefined for zero budget', () => {
-    const suite: JsonObject = { execution: { total_budget_usd: 0 } };
-    expect(extractTotalBudgetUsd(suite)).toBeUndefined();
+    const suite: JsonObject = { execution: { budget_usd: 0 } };
+    expect(extractBudgetUsd(suite)).toBeUndefined();
   });
 
   it('returns undefined for negative budget', () => {
-    const suite: JsonObject = { execution: { total_budget_usd: -1 } };
-    expect(extractTotalBudgetUsd(suite)).toBeUndefined();
+    const suite: JsonObject = { execution: { budget_usd: -1 } };
+    expect(extractBudgetUsd(suite)).toBeUndefined();
   });
 
   it('returns undefined for non-number budget', () => {
-    const suite: JsonObject = { execution: { total_budget_usd: 'ten' } };
-    expect(extractTotalBudgetUsd(suite)).toBeUndefined();
+    const suite: JsonObject = { execution: { budget_usd: 'ten' } };
+    expect(extractBudgetUsd(suite)).toBeUndefined();
+  });
+
+  it('rejects old key total_budget_usd with a clear error', () => {
+    const suite: JsonObject = { execution: { total_budget_usd: 10.0 } };
+    expect(() => extractBudgetUsd(suite)).toThrow(
+      'execution.total_budget_usd has been renamed to execution.budget_usd. Update your eval YAML.',
+    );
+  });
+
+  it('rejects old key totalBudgetUsd with a clear error', () => {
+    const suite: JsonObject = { execution: { totalBudgetUsd: 10.0 } };
+    expect(() => extractBudgetUsd(suite)).toThrow(
+      'execution.total_budget_usd has been renamed to execution.budget_usd. Update your eval YAML.',
+    );
   });
 });
 
diff --git a/packages/core/test/evaluation/orchestrator.test.ts b/packages/core/test/evaluation/orchestrator.test.ts
index 70e75bad..a5a29084 100644
--- a/packages/core/test/evaluation/orchestrator.test.ts
+++ b/packages/core/test/evaluation/orchestrator.test.ts
@@ -2507,7 +2507,7 @@ describe('workspace.template .code-workspace resolution', () => {
 });
 
 describe('suite-level total budget guardrail', () => {
-  it('completes normally when totalBudgetUsd is not set', async () => {
+  it('completes normally when budgetUsd is not set', async () => {
     const provider: Provider = {
       id: 'budget:mock',
       kind: 'mock' as const,
@@ -2564,7 +2564,7 @@ describe('suite-level total budget guardrail', () => {
       providerFactory: () => provider,
       evaluators: evaluatorRegistry,
       evalCases,
-      totalBudgetUsd: 10.0,
+      budgetUsd: 10.0,
     });
 
     expect(results).toHaveLength(2);
@@ -2598,7 +2598,7 @@ describe('suite-level total budget guardrail', () => {
       providerFactory: () => provider,
       evaluators: evaluatorRegistry,
       evalCases,
-      totalBudgetUsd: 5.0,
+      budgetUsd: 5.0,
       maxConcurrency: 1,
     });
 
@@ -2647,7 +2647,7 @@ describe('suite-level total budget guardrail', () => {
       providerFactory: () => provider,
       evaluators: evaluatorRegistry,
       evalCases,
-      totalBudgetUsd: 5.0,
+      budgetUsd: 5.0,
       maxConcurrency: 1,
       trials: { count: 2, strategy: 'pass_at_k' },
     });
diff --git a/plugins/agentv-dev/skills/agentv-eval-writer/references/eval-schema.json b/plugins/agentv-dev/skills/agentv-eval-writer/references/eval-schema.json
index e515225b..2f6fd88a 100644
--- a/plugins/agentv-dev/skills/agentv-eval-writer/references/eval-schema.json
+++ b/plugins/agentv-dev/skills/agentv-eval-writer/references/eval-schema.json
@@ -5015,11 +5015,11 @@
                         "required": ["count"],
                         "additionalProperties": false
                       },
-                      "total_budget_usd": {
+                      "budget_usd": {
                         "type": "number",
                         "minimum": 0
                       },
-                      "totalBudgetUsd": {
+                      "budgetUsd": {
                         "type": "number",
                         "minimum": 0
                       },
@@ -11543,11 +11543,11 @@
                         "required": ["count"],
                         "additionalProperties": false
                       },
-                      "total_budget_usd": {
+                      "budget_usd": {
                         "type": "number",
                         "minimum": 0
                       },
-                      "totalBudgetUsd": {
+                      "budgetUsd": {
                         "type": "number",
                         "minimum": 0
                       },
@@ -15682,11 +15682,11 @@
               "required": ["count"],
               "additionalProperties": false
             },
-            "total_budget_usd": {
+            "budget_usd": {
               "type": "number",
               "minimum": 0
             },
-            "totalBudgetUsd": {
+            "budgetUsd": {
               "type": "number",
               "minimum": 0
             },