diff --git a/src/server/registerArtifactTools.ts b/src/server/registerArtifactTools.ts
index c0455af7bd..7b6a8656db 100644
--- a/src/server/registerArtifactTools.ts
+++ b/src/server/registerArtifactTools.ts
@@ -4,10 +4,7 @@ import {
 } from "../domain/immutableJson.js";
 import type { EvidenceMcpServer } from "./EvidenceMcpServer.js";
 
-import {
-  ARTIFACT_TOOL_CONTRACTS,
-  artifactInspectionInputSchema,
-} from "../contracts/artifactToolContracts.js";
+import { ARTIFACT_TOOL_CONTRACTS } from "../contracts/artifactToolContracts.js";
 import { createArtifactExtractionDestination } from "../application/artifacts/ArtifactExtractionDestination.js";
 import { registerEvidenceTools } from "./registerEvidenceTools.js";
 import { artifactInspectionResultSchema } from "../domain/artifactInspection.js";
@@ -22,6 +19,7 @@ const SUMMARY_DELIVERY: ReadonlySet<string> = new Set([
   "inspect_artifact",
   "decode_interface_builder",
 ]);
+const executionWithoutDelivery = withoutDeliveryDetail(SUMMARY_DELIVERY);
 /** inspect_artifact keeps an explicit detail in its Evidence parameters. */
 const decodeWithoutDelivery = withoutDeliveryDetail(
   new Set(["decode_interface_builder"]),
@@ -35,16 +33,10 @@ export const registerArtifactTools = (
   registerEvidenceTools(server, ARTIFACT_TOOL_CONTRACTS, {
     ...options,
     ...retainedSummaryDelivery(SUMMARY_DELIVERY, options),
-    parametersForExecution: (operation, parameters) => {
-      if (operation === "inspect_artifact") {
-        const { detail: _detail, ...execution } =
-          artifactInspectionInputSchema.parse(parameters);
-        return execution;
-      }
-      return operation === "extract_artifact"
+    parametersForExecution: (operation, parameters) =>
+      operation === "extract_artifact"
         ? { ...parameters, output_root: createArtifactExtractionDestination() }
-        : decodeWithoutDelivery(operation, parameters);
-    },
+        : executionWithoutDelivery(operation, parameters),
     parametersForEvidence: decodeWithoutDelivery,
     sourceEvidence: (operation, result) => {
       if (operation !== "inspect_artifact") return [];
diff --git a/src/server/registerEvidenceTools.ts b/src/server/registerEvidenceTools.ts
index 6d87921842..cf1f71cf2d 100644
--- a/src/server/registerEvidenceTools.ts
+++ b/src/server/registerEvidenceTools.ts
@@ -61,10 +61,8 @@ export const registerEvidenceTools = (
       contract.name,
       toolRegistrationOptions(contract),
       async (input, context) => {
-        const ready = options.preflight?.(
-          contract.name,
-          jsonObjectSchema.parse(input),
-        );
+        const parameters = jsonObjectSchema.parse(input);
+        const ready = options.preflight?.(contract.name, parameters);
         if (ready !== undefined && !ready.ok)
           return server.delivery.toCallToolResult(ready, contract);
         const admitted = await options.withAdmittedAnalysis(
@@ -81,7 +79,6 @@ export const registerEvidenceTools = (
               total: 1,
               message: "started",
             });
-            const parameters = jsonObjectSchema.parse(input);
             const executionParameters =
               options.parametersForExecution?.(contract.name, parameters) ??
               parameters;