diff --git a/src/application/BinaryTargetResolver.ts b/src/application/BinaryTargetResolver.ts
index 0cffae284f..078fc64310 100644
--- a/src/application/BinaryTargetResolver.ts
+++ b/src/application/BinaryTargetResolver.ts
@@ -93,6 +93,7 @@ export const parseBinaryTarget = async (
             new BinaryTargetError(
               path,
               "raw-binary format requires an executable target kind",
+              { constraint: "file_format_rejected" },
             ),
           );
         const admitted = admitRawBinary({
@@ -101,7 +102,11 @@ export const parseBinaryTarget = async (
           fileBytes: metadata.size,
         });
         if (!admitted.ok)
-          return err(new BinaryTargetError(path, admitted.error));
+          return err(
+            new BinaryTargetError(path, admitted.error, {
+              constraint: "file_format_rejected",
+            }),
+          );
         return ok({
           path,
           sourcePath: canonical,
@@ -127,10 +132,16 @@ export const parseBinaryTarget = async (
             new BinaryTargetError(
               path,
               "DOS COM format requires an executable target kind",
+              { constraint: "file_format_rejected" },
             ),
           );
         const length = validateDosComLength(metadata.size);
-        if (!length.ok) return err(new BinaryTargetError(path, length.error));
+        if (!length.ok)
+          return err(
+            new BinaryTargetError(path, length.error, {
+              constraint: "file_format_rejected",
+            }),
+          );
         return ok({
           path,
           sourcePath: canonical,
@@ -168,7 +179,12 @@ export const parseBinaryTarget = async (
         hostArchitecture,
         signal,
       );
-      if (!detected.ok) return err(new BinaryTargetError(path, detected.error));
+      if (!detected.ok)
+        return err(
+          new BinaryTargetError(path, detected.error, {
+            constraint: "file_format_rejected",
+          }),
+        );
       return ok({
         path,
         sourcePath: process.platform === "win32" ? candidate : canonical,
diff --git a/src/domain/analysisErrorPresentation.ts b/src/domain/analysisErrorPresentation.ts
index c28f926b57..9e4ee3a2a4 100644
--- a/src/domain/analysisErrorPresentation.ts
+++ b/src/domain/analysisErrorPresentation.ts
@@ -76,6 +76,11 @@ export const analysisErrorRemediationAction = (
     error.constraint === "directory_requires_file"
   )
     return "For a JavaScript/Electron application directory, call analyze_javascript_application with input_path or run `rea analyze <directory>`. For binary analysis, select its executable file.";
+  if (
+    error instanceof BinaryTargetError &&
+    error.constraint === "file_format_rejected"
+  )
+    return "Review the reported file-format reason and select a supported, well-formed target.";
   if (
     error instanceof BinaryTargetError &&
     error.constraint === "wasm_requires_static_inspection"
@@ -102,7 +107,8 @@ export const analysisErrorCategory = (
 ): AnalysisErrorProjection["category"] => {
   if (
     error instanceof BinaryTargetError &&
-    error.constraint === "wasm_requires_static_inspection"
+    (error.constraint === "wasm_requires_static_inspection" ||
+      error.constraint === "file_format_rejected")
   )
     return "unsupported_target";
   if (
@@ -231,7 +237,9 @@ export const analysisErrorUserMessage = (error: AnalysisError): string => {
   if (error instanceof BinaryTargetError)
     return error.constraint === "directory_requires_file"
       ? "open_binary accepts files and macOS app bundles. This target is a directory; JavaScript/Electron application directories can be analyzed directly with analyze_javascript_application or `rea analyze <directory>`."
-      : `${error.message}. Check that the path exists, is readable, and points to a supported file.`;
+      : error.constraint === "file_format_rejected"
+        ? `${error.message}.`
+        : `${error.message}. Check that the path exists, is readable, and points to a supported file.`;
   if (error._tag === "ProcessCaptureError")
     return (
       error.userMessage ??
diff --git a/src/domain/configurationErrors.ts b/src/domain/configurationErrors.ts
index 803a21a652..ab60e354cd 100644
--- a/src/domain/configurationErrors.ts
+++ b/src/domain/configurationErrors.ts
@@ -40,7 +40,8 @@ export class NoBinaryOpenError extends AnalysisError {
 export interface BinaryTargetErrorOptions extends AnalysisErrorOptions {
   readonly constraint?:
     | "directory_requires_file"
-    | "wasm_requires_static_inspection";
+    | "wasm_requires_static_inspection"
+    | "file_format_rejected";
 }
 
 /** A supplied target path could not be safely opened as a supported app or binary. */
diff --git a/tests/boundary/filesystem/targetDiagnostics.test.ts b/tests/boundary/filesystem/targetDiagnostics.test.ts
index 32b86bbceb..85b7a70456 100644
--- a/tests/boundary/filesystem/targetDiagnostics.test.ts
+++ b/tests/boundary/filesystem/targetDiagnostics.test.ts
@@ -6,6 +6,51 @@ import { parseBinaryTarget } from "../../../src/application/BinaryTargetResolver
 import { projectAnalysisError } from "../../../src/domain/analysisErrorProjection.js";
 import { createTestTempDirectory } from "../../fixtures/temporaryDirectory.js";
 
+describe("executable format refusal diagnostics", () => {
+  it.each(["NE", "LE", "LX"] as const)(
+    "reports unsupported %s executables without path advice",
+    async (signature) => {
+      const directory = await createTestTempDirectory(
+        `rea-target-${signature.toLowerCase()}-`,
+      );
+      const path = join(directory, "unsupported.exe");
+      const bytes = Buffer.alloc(0x80 + 24);
+      bytes.write("MZ", 0, "ascii");
+      bytes.writeUInt32LE(0x80, 0x3c);
+      bytes.write(signature, 0x80, "ascii");
+      await writeFile(path, bytes);
+
+      const result = await parseBinaryTarget(path);
+      if (result.ok)
+        throw new Error(`unsupported ${signature} target was admitted`);
+      const reason = `unsupported ${signature} executable in MZ image`;
+      const projected = projectAnalysisError(result.error);
+      expect(projected).toMatchObject({
+        code: "target_unavailable",
+        category: "unsupported_target",
+        retryable: false,
+        message: `Cannot open artifact: ${reason}.`,
+        details: {
+          reason,
+          constraint: "file_format_rejected",
+        },
+        remediation: {
+          action:
+            "Review the reported file-format reason and select a supported, well-formed target.",
+        },
+      });
+      expect(projected.message).not.toContain("Check that the path");
+
+      expect(await systemDoctorHost().inspectTarget?.(path)).toMatchObject({
+        classification: "unsupported_target",
+        details: { constraint: "file_format_rejected" },
+        remediation:
+          "Review the reported file-format reason and select a supported, well-formed target.",
+      });
+    },
+  );
+});
+
 describe("target route diagnostics", () => {
   it.each(["module.wasm", "module.bin", "misleading.js"])(
     "identifies a WASM v1 header in %s without suggesting native provider installation",
@@ -53,7 +98,11 @@ describe("target route diagnostics", () => {
       const result = await parseBinaryTarget(path);
       if (result.ok) throw new Error("unknown header was admitted");
       const projected = projectAnalysisError(result.error);
-      expect(projected.details).not.toHaveProperty("constraint");
+      expect(projected).toMatchObject({
+        category: "unsupported_target",
+        retryable: false,
+        details: { constraint: "file_format_rejected" },
+      });
       expect(projected.remediation.action).not.toContain(
         "inspect_wasm_artifact",
       );
@@ -107,10 +156,14 @@ describe("target route diagnostics", () => {
     });
     const missing = await parseBinaryTarget(join(directory, "missing"));
     if (missing.ok) throw new Error("missing target was admitted");
-    expect(projectAnalysisError(missing.error)).toMatchObject({
+    const missingProjection = projectAnalysisError(missing.error);
+    expect(missingProjection).toMatchObject({
       details: { reason: expect.stringContaining("does not exist") },
       message: expect.stringContaining("does not exist"),
     });
+    expect(missingProjection.message).toContain(
+      "Check that the path exists, is readable, and points to a supported file.",
+    );
     expect(
       await doctor.inspectTarget?.(join(directory, "missing")),
     ).toMatchObject({
@@ -129,10 +182,14 @@ describe("target route diagnostics", () => {
       try {
         const result = await parseBinaryTarget(path);
         if (result.ok) throw new Error("unreadable target was admitted");
-        expect(projectAnalysisError(result.error)).toMatchObject({
+        const projected = projectAnalysisError(result.error);
+        expect(projected).toMatchObject({
           details: { reason: expect.stringContaining("permission denied") },
           message: expect.stringContaining("permission denied"),
         });
+        expect(projected.message).toContain(
+          "Check that the path exists, is readable, and points to a supported file.",
+        );
         expect(await systemDoctorHost().inspectTarget?.(path)).toMatchObject({
           ok: false,
           classification: "config_drift",