diff --git a/eslint-factory/src/rules/no-json-stringify-error.test.ts b/eslint-factory/src/rules/no-json-stringify-error.test.ts
index 76100f6b42e..c2f4c11347a 100644
--- a/eslint-factory/src/rules/no-json-stringify-error.test.ts
+++ b/eslint-factory/src/rules/no-json-stringify-error.test.ts
@@ -75,9 +75,14 @@ describe("no-json-stringify-error", () => {
               data: { errorVar: "err" },
               suggestions: [
                 {
-                  messageId: "useGetErrorMessage",
+                  messageId: "useStringFallback",
+                  data: { errorVar: "err" },
+                  output: `try { f(); } catch (err) { core.error(String(err)); }`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
                   data: { errorVar: "err" },
-                  output: `try { f(); } catch (err) { core.error(getErrorMessage(err)); }`,
+                  output: 'try { f(); } catch (err) { core.error((String(err) + "\\n" + (err?.stack ?? ""))); }',
                 },
               ],
             },
@@ -99,9 +104,14 @@ describe("no-json-stringify-error", () => {
               data: { errorVar: "error" },
               suggestions: [
                 {
-                  messageId: "useGetErrorMessage",
+                  messageId: "useStringFallback",
+                  data: { errorVar: "error" },
+                  output: `try { f(); } catch (error) { core.error(\`details: \${String(error)}\`); }`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
                   data: { errorVar: "error" },
-                  output: `try { f(); } catch (error) { core.error(\`details: \${getErrorMessage(error)}\`); }`,
+                  output: 'try { f(); } catch (error) { core.error(`details: ${(String(error) + "\\n" + (error?.stack ?? ""))}`); }',
                 },
               ],
             },
@@ -123,9 +133,14 @@ describe("no-json-stringify-error", () => {
               data: { errorVar: "err" },
               suggestions: [
                 {
-                  messageId: "useGetErrorMessage",
+                  messageId: "useStringFallback",
+                  data: { errorVar: "err" },
+                  output: `p.catch(err => core.error(String(err)));`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
                   data: { errorVar: "err" },
-                  output: `p.catch(err => core.error(getErrorMessage(err)));`,
+                  output: 'p.catch(err => core.error((String(err) + "\\n" + (err?.stack ?? ""))));',
                 },
               ],
             },
@@ -147,9 +162,14 @@ describe("no-json-stringify-error", () => {
               data: { errorVar: "err" },
               suggestions: [
                 {
-                  messageId: "useGetErrorMessage",
+                  messageId: "useStringFallback",
+                  data: { errorVar: "err" },
+                  output: `p.catch(function(err) { core.error(String(err)); });`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
                   data: { errorVar: "err" },
-                  output: `p.catch(function(err) { core.error(getErrorMessage(err)); });`,
+                  output: 'p.catch(function(err) { core.error((String(err) + "\\n" + (err?.stack ?? ""))); });',
                 },
               ],
             },
@@ -171,9 +191,14 @@ describe("no-json-stringify-error", () => {
               data: { errorVar: "outer" },
               suggestions: [
                 {
-                  messageId: "useGetErrorMessage",
+                  messageId: "useStringFallback",
+                  data: { errorVar: "outer" },
+                  output: `try { f(); } catch (outer) { try { g(); } catch (inner) { } core.error(String(outer)); }`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
                   data: { errorVar: "outer" },
-                  output: `try { f(); } catch (outer) { try { g(); } catch (inner) { } core.error(getErrorMessage(outer)); }`,
+                  output: 'try { f(); } catch (outer) { try { g(); } catch (inner) { } core.error((String(outer) + "\\n" + (outer?.stack ?? ""))); }',
                 },
               ],
             },
@@ -209,9 +234,14 @@ describe("no-json-stringify-error", () => {
               data: { errorVar: "err" },
               suggestions: [
                 {
-                  messageId: "useGetErrorMessage",
+                  messageId: "useStringFallback",
                   data: { errorVar: "err" },
-                  output: `p.then(result => result, err => core.error(getErrorMessage(err)));`,
+                  output: `p.then(result => result, err => core.error(String(err)));`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
+                  data: { errorVar: "err" },
+                  output: 'p.then(result => result, err => core.error((String(err) + "\\n" + (err?.stack ?? ""))));',
                 },
               ],
             },
@@ -225,9 +255,14 @@ describe("no-json-stringify-error", () => {
               data: { errorVar: "err" },
               suggestions: [
                 {
-                  messageId: "useGetErrorMessage",
+                  messageId: "useStringFallback",
                   data: { errorVar: "err" },
-                  output: `p.then(null, err => core.error(getErrorMessage(err)));`,
+                  output: `p.then(null, err => core.error(String(err)));`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
+                  data: { errorVar: "err" },
+                  output: 'p.then(null, err => core.error((String(err) + "\\n" + (err?.stack ?? ""))));',
                 },
               ],
             },
@@ -249,9 +284,14 @@ describe("no-json-stringify-error", () => {
               data: { errorVar: "err" },
               suggestions: [
                 {
-                  messageId: "useGetErrorMessage",
+                  messageId: "useStringFallback",
                   data: { errorVar: "err" },
-                  output: `p.then(null, function(err) { core.error(getErrorMessage(err)); });`,
+                  output: `p.then(null, function(err) { core.error(String(err)); });`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
+                  data: { errorVar: "err" },
+                  output: 'p.then(null, function(err) { core.error((String(err) + "\\n" + (err?.stack ?? ""))); });',
                 },
               ],
             },
@@ -280,9 +320,14 @@ describe("no-json-stringify-error", () => {
               data: { errorVar: "e" },
               suggestions: [
                 {
-                  messageId: "useGetErrorMessage",
+                  messageId: "useStringFallback",
+                  data: { errorVar: "e" },
+                  output: `try { fetch(url); } catch (e) { console.error(String(e)); }`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
                   data: { errorVar: "e" },
-                  output: `try { fetch(url); } catch (e) { console.error(getErrorMessage(e)); }`,
+                  output: 'try { fetch(url); } catch (e) { console.error((String(e) + "\\n" + (e?.stack ?? ""))); }',
                 },
               ],
             },
@@ -296,9 +341,14 @@ describe("no-json-stringify-error", () => {
               data: { errorVar: "err" },
               suggestions: [
                 {
-                  messageId: "useGetErrorMessage",
+                  messageId: "useStringFallback",
                   data: { errorVar: "err" },
-                  output: `p.then(ok, err => console.error(getErrorMessage(err)));`,
+                  output: `p.then(ok, err => console.error(String(err)));`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
+                  data: { errorVar: "err" },
+                  output: 'p.then(ok, err => console.error((String(err) + "\\n" + (err?.stack ?? ""))));',
                 },
               ],
             },
@@ -320,9 +370,246 @@ describe("no-json-stringify-error", () => {
               data: { errorVar: "inner" },
               suggestions: [
                 {
-                  messageId: "useGetErrorMessage",
+                  messageId: "useStringFallback",
                   data: { errorVar: "inner" },
-                  output: `try { f(); } catch (outer) { try { g(); } catch (inner) { core.error(getErrorMessage(inner)); } }`,
+                  output: `try { f(); } catch (outer) { try { g(); } catch (inner) { core.error(String(inner)); } }`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
+                  data: { errorVar: "inner" },
+                  output: 'try { f(); } catch (outer) { try { g(); } catch (inner) { core.error((String(inner) + "\\n" + (inner?.stack ?? ""))); } }',
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("invalid: when getErrorMessage is in scope, suggests getErrorMessage and detail-preserving form", () => {
+    cjsRuleTester.run("no-json-stringify-error", noJsonStringifyErrorRule, {
+      valid: [],
+      invalid: [
+        {
+          code: `const getErrorMessage = require('./error_helpers').getErrorMessage; try { f(); } catch (err) { core.error(JSON.stringify(err)); }`,
+          errors: [
+            {
+              messageId: "jsonStringifyError",
+              data: { errorVar: "err" },
+              suggestions: [
+                {
+                  messageId: "useGetErrorMessage",
+                  data: { errorVar: "err" },
+                  output: `const getErrorMessage = require('./error_helpers').getErrorMessage; try { f(); } catch (err) { core.error(getErrorMessage(err)); }`,
+                },
+                {
+                  messageId: "useDetailPreservingForm",
+                  data: { errorVar: "err" },
+                  output: 'const getErrorMessage = require(\'./error_helpers\').getErrorMessage; try { f(); } catch (err) { core.error((getErrorMessage(err) + "\\n" + (err?.stack ?? ""))); }',
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("invalid: when getErrorMessage is in scope via destructured require, detail-preserving form uses getErrorMessage", () => {
+    cjsRuleTester.run("no-json-stringify-error", noJsonStringifyErrorRule, {
+      valid: [],
+      invalid: [
+        {
+          code: `const { getErrorMessage } = require('./error_helpers'); try { f(); } catch (error) { core.error(\`details: \${JSON.stringify(error, null, 2)}\`); }`,
+          errors: [
+            {
+              messageId: "jsonStringifyError",
+              data: { errorVar: "error" },
+              suggestions: [
+                {
+                  messageId: "useGetErrorMessage",
+                  data: { errorVar: "error" },
+                  output: `const { getErrorMessage } = require('./error_helpers'); try { f(); } catch (error) { core.error(\`details: \${getErrorMessage(error)}\`); }`,
+                },
+                {
+                  messageId: "useDetailPreservingForm",
+                  data: { errorVar: "error" },
+                  output: 'const { getErrorMessage } = require(\'./error_helpers\'); try { f(); } catch (error) { core.error(`details: ${(getErrorMessage(error) + "\\n" + (error?.stack ?? ""))}`); }',
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("invalid: when getErrorMessage is imported via ESM, suggestions use getErrorMessage", () => {
+    esmRuleTester.run("no-json-stringify-error", noJsonStringifyErrorRule, {
+      valid: [],
+      invalid: [
+        {
+          code: `import { getErrorMessage } from "./error_helpers"; try { f(); } catch (err) { console.error(JSON.stringify(err)); }`,
+          errors: [
+            {
+              messageId: "jsonStringifyError",
+              data: { errorVar: "err" },
+              suggestions: [
+                {
+                  messageId: "useGetErrorMessage",
+                  data: { errorVar: "err" },
+                  output: `import { getErrorMessage } from "./error_helpers"; try { f(); } catch (err) { console.error(getErrorMessage(err)); }`,
+                },
+                {
+                  messageId: "useDetailPreservingForm",
+                  data: { errorVar: "err" },
+                  output: 'import { getErrorMessage } from "./error_helpers"; try { f(); } catch (err) { console.error((getErrorMessage(err) + "\\n" + (err?.stack ?? ""))); }',
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("invalid: when getErrorMessage is declared earlier in the catch block, suggestions use getErrorMessage", () => {
+    cjsRuleTester.run("no-json-stringify-error", noJsonStringifyErrorRule, {
+      valid: [],
+      invalid: [
+        {
+          code: `try { f(); } catch (err) { const getErrorMessage = customHelper; console.error(JSON.stringify(err)); }`,
+          errors: [
+            {
+              messageId: "jsonStringifyError",
+              data: { errorVar: "err" },
+              suggestions: [
+                {
+                  messageId: "useGetErrorMessage",
+                  data: { errorVar: "err" },
+                  output: `try { f(); } catch (err) { const getErrorMessage = customHelper; console.error(getErrorMessage(err)); }`,
+                },
+                {
+                  messageId: "useDetailPreservingForm",
+                  data: { errorVar: "err" },
+                  output: 'try { f(); } catch (err) { const getErrorMessage = customHelper; console.error((getErrorMessage(err) + "\\n" + (err?.stack ?? ""))); }',
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("invalid: when getErrorMessage is declared after the call site, suggestions fall back to String()", () => {
+    cjsRuleTester.run("no-json-stringify-error", noJsonStringifyErrorRule, {
+      valid: [],
+      invalid: [
+        {
+          code: `try { f(); } catch (err) { console.error(JSON.stringify(err)); const getErrorMessage = customHelper; }`,
+          errors: [
+            {
+              messageId: "jsonStringifyError",
+              data: { errorVar: "err" },
+              suggestions: [
+                {
+                  messageId: "useStringFallback",
+                  data: { errorVar: "err" },
+                  output: `try { f(); } catch (err) { console.error(String(err)); const getErrorMessage = customHelper; }`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
+                  data: { errorVar: "err" },
+                  output: 'try { f(); } catch (err) { console.error((String(err) + "\\n" + (err?.stack ?? ""))); const getErrorMessage = customHelper; }',
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("invalid: detail-preserving suggestion is parenthesized when the call is chained", () => {
+    cjsRuleTester.run("no-json-stringify-error", noJsonStringifyErrorRule, {
+      valid: [],
+      invalid: [
+        {
+          code: `try { f(); } catch (err) { console.error(JSON.stringify(err).slice(0, 20)); }`,
+          errors: [
+            {
+              messageId: "jsonStringifyError",
+              data: { errorVar: "err" },
+              suggestions: [
+                {
+                  messageId: "useStringFallback",
+                  data: { errorVar: "err" },
+                  output: `try { f(); } catch (err) { console.error(String(err).slice(0, 20)); }`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
+                  data: { errorVar: "err" },
+                  output: 'try { f(); } catch (err) { console.error((String(err) + "\\n" + (err?.stack ?? "")).slice(0, 20)); }',
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("invalid: when getErrorMessage is in scope inside a promise rejection handler, suggestions use getErrorMessage", () => {
+    cjsRuleTester.run("no-json-stringify-error", noJsonStringifyErrorRule, {
+      valid: [],
+      invalid: [
+        {
+          code: `const { getErrorMessage } = require('./error_helpers'); p.catch(err => console.error(JSON.stringify(err)));`,
+          errors: [
+            {
+              messageId: "jsonStringifyError",
+              data: { errorVar: "err" },
+              suggestions: [
+                {
+                  messageId: "useGetErrorMessage",
+                  data: { errorVar: "err" },
+                  output: `const { getErrorMessage } = require('./error_helpers'); p.catch(err => console.error(getErrorMessage(err)));`,
+                },
+                {
+                  messageId: "useDetailPreservingForm",
+                  data: { errorVar: "err" },
+                  output: 'const { getErrorMessage } = require(\'./error_helpers\'); p.catch(err => console.error((getErrorMessage(err) + "\\n" + (err?.stack ?? ""))));',
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("invalid: when getErrorMessage is not in scope, first suggestion uses String() fallback", () => {
+    cjsRuleTester.run("no-json-stringify-error", noJsonStringifyErrorRule, {
+      valid: [],
+      invalid: [
+        {
+          code: `try { f(); } catch (err) { console.error(JSON.stringify(err)); }`,
+          errors: [
+            {
+              messageId: "jsonStringifyError",
+              data: { errorVar: "err" },
+              suggestions: [
+                {
+                  messageId: "useStringFallback",
+                  data: { errorVar: "err" },
+                  output: `try { f(); } catch (err) { console.error(String(err)); }`,
+                },
+                {
+                  messageId: "useDetailPreservingFormFallback",
+                  data: { errorVar: "err" },
+                  output: 'try { f(); } catch (err) { console.error((String(err) + "\\n" + (err?.stack ?? ""))); }',
                 },
               ],
             },
diff --git a/eslint-factory/src/rules/no-json-stringify-error.ts b/eslint-factory/src/rules/no-json-stringify-error.ts
index 5ba4e56773e..e1b6d8cfb08 100644
--- a/eslint-factory/src/rules/no-json-stringify-error.ts
+++ b/eslint-factory/src/rules/no-json-stringify-error.ts
@@ -46,12 +46,18 @@ export const noJsonStringifyErrorRule = createRule({
     schema: [],
     messages: {
       jsonStringifyError:
-        "JSON.stringify({{errorVar}}) produces {} for Error objects — Error properties (message, stack, etc.) are non-enumerable. Prefer getErrorMessage({{errorVar}}) from error_helpers.cjs or explicitly serialize a guarded value after narrowing it.",
+        "JSON.stringify({{errorVar}}) produces {} for Error objects — Error properties (message, stack, etc.) are non-enumerable. Use getErrorMessage({{errorVar}}) if it is available, or String({{errorVar}}) as a safe import-free alternative.",
       useGetErrorMessage: "Replace with getErrorMessage({{errorVar}}) — ensure getErrorMessage is imported from error_helpers.cjs.",
+      useStringFallback: "Replace with String({{errorVar}}) — getErrorMessage is not in scope; String() is a safe import-free alternative.",
+      useDetailPreservingForm: 'Replace with (getErrorMessage({{errorVar}}) + "\\n" + ({{errorVar}}?.stack ?? "")) to preserve the stack trace — ensure getErrorMessage is imported from error_helpers.cjs.',
+      useDetailPreservingFormFallback: 'Replace with (String({{errorVar}}) + "\\n" + ({{errorVar}}?.stack ?? "")) to preserve the stack trace.',
     },
   },
   defaultOptions: [],
   create(context) {
+    const sourceCode = context.sourceCode;
+    type SourceCodeScope = ReturnType<typeof sourceCode.getScope>;
+
     // Stack tracking caught error variable names.
     // Each scope entry holds varName (empty string for sentinel) and isSentinel flag.
     const scopeStack: ErrorScope[] = [];
@@ -87,6 +93,30 @@ export const noJsonStringifyErrorRule = createRule({
       scopeStack.pop();
     }
 
+    function isDefinitionAvailableAtNode(definition: { type: string; name?: TSESTree.Node | null; node: TSESTree.Node }, node: TSESTree.Node): boolean {
+      if (definition.type === "ImportBinding" || definition.type === "FunctionName") {
+        return true;
+      }
+
+      const definitionNode = definition.name ?? definition.node;
+      return definitionNode.range[0] < node.range[0];
+    }
+
+    function hasResolvableLocalBinding(node: TSESTree.Node, name: string): boolean {
+      let scope: SourceCodeScope | null = sourceCode.getScope(node);
+
+      while (scope) {
+        const variable = scope.set.get(name);
+        if (variable && variable.defs.some(definition => isDefinitionAvailableAtNode(definition, node))) {
+          return true;
+        }
+
+        scope = scope.upper;
+      }
+
+      return false;
+    }
+
     return {
       // Track catch clause parameters
       CatchClause(node) {
@@ -125,18 +155,46 @@ export const noJsonStringifyErrorRule = createRule({
         if (!caughtNames.has(firstArg.name)) return;
 
         const errorVar = firstArg.name;
+
+        const getErrorMessageInScope = hasResolvableLocalBinding(node, "getErrorMessage");
+
         context.report({
           node,
           messageId: "jsonStringifyError",
           data: { errorVar },
           suggest: [
-            {
-              messageId: "useGetErrorMessage" as const,
-              data: { errorVar },
-              fix(fixer) {
-                return fixer.replaceText(node, `getErrorMessage(${errorVar})`);
-              },
-            },
+            // Suggestion 1: concise message-only replacement
+            getErrorMessageInScope
+              ? ({
+                  messageId: "useGetErrorMessage" as const,
+                  data: { errorVar },
+                  fix(fixer) {
+                    return fixer.replaceText(node, `getErrorMessage(${errorVar})`);
+                  },
+                } as const)
+              : ({
+                  messageId: "useStringFallback" as const,
+                  data: { errorVar },
+                  fix(fixer) {
+                    return fixer.replaceText(node, `String(${errorVar})`);
+                  },
+                } as const),
+            // Suggestion 2: detail-preserving replacement (retains stack trace)
+            getErrorMessageInScope
+              ? ({
+                  messageId: "useDetailPreservingForm" as const,
+                  data: { errorVar },
+                  fix(fixer) {
+                    return fixer.replaceText(node, `(getErrorMessage(${errorVar}) + "\\n" + (${errorVar}?.stack ?? ""))`);
+                  },
+                } as const)
+              : ({
+                  messageId: "useDetailPreservingFormFallback" as const,
+                  data: { errorVar },
+                  fix(fixer) {
+                    return fixer.replaceText(node, `(String(${errorVar}) + "\\n" + (${errorVar}?.stack ?? ""))`);
+                  },
+                } as const),
           ],
         });
       },