fix(cli): keep array examples type-correct

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## [0.12.3] - Unreleased
 
-- Nothing yet.
+- Render list signatures and call examples from array item schemas, keeping number, boolean, object, and unknown arrays type-correct. (Issue #221, thanks @VincXiong)
 
 ## [0.12.2] - 2026-06-27
 

src/cli/generate/tools.ts

@@ -100,7 +100,7 @@ export function extractOptions(tool: ServerToolInfo): GeneratedOption[] {
     const defaultValue = getDescriptorDefault(descriptor);
     const formatInfo = getDescriptorFormatHint(descriptor);
     const placeholder = buildPlaceholder(property, type, enumValues, formatInfo?.slug);
-    const exampleValue = buildExampleValue(property, type, enumValues, defaultValue);
+    const exampleValue = buildExampleValue(property, type, enumValues, defaultValue, arrayItemType);
     return {
       property,
       cliName: toCliOption(property),
@@ -181,7 +181,8 @@ export function buildExampleValue(
   property: string,
   type: GeneratedOption['type'],
   enumValues: string[] | undefined,
-  defaultValue: unknown
+  defaultValue: unknown,
+  arrayItemType?: GeneratedOption['arrayItemType']
 ): string | undefined {
   if (enumValues && enumValues.length > 0) {
     return enumValues[0] as string;
@@ -199,7 +200,16 @@ export function buildExampleValue(
     case 'boolean':
       return 'true';
     case 'array':
-      return 'value1,value2';
+      switch (arrayItemType) {
+        case 'number':
+          return '1,2';
+        case 'boolean':
+          return 'true,false';
+        case 'object':
+          return '[{"key":"value"}]';
+        default:
+          return 'value1,value2';
+      }
     case 'object':
       return '{"key":"value"}';
     default:
@@ -214,6 +224,28 @@ export function buildExampleValue(
 }
 
 export function pickExampleLiteral(option: GeneratedOption): string | undefined {
+  if (option.type === 'array') {
+    if (Array.isArray(option.defaultValue)) {
+      try {
+        return JSON.stringify(option.defaultValue);
+      } catch {
+        return undefined;
+      }
+    }
+    if (option.enumValues && option.enumValues.length > 0) {
+      return JSON.stringify([option.enumValues[0]]);
+    }
+    switch (option.arrayItemType) {
+      case 'number':
+        return '[1, 2]';
+      case 'boolean':
+        return '[true, false]';
+      case 'object':
+        return '[{"key":"value"}]';
+      default:
+        break;
+    }
+  }
   if (option.enumValues && option.enumValues.length > 0) {
     return JSON.stringify(option.enumValues[0]);
   }
@@ -251,7 +283,16 @@ export function buildFallbackLiteral(option: GeneratedOption): string {
     case 'boolean':
       return 'true';
     case 'array':
-      return '["value1"]';
+      switch (option.arrayItemType) {
+        case 'number':
+          return '[1]';
+        case 'boolean':
+          return '[true]';
+        case 'object':
+          return '[{"key":"value"}]';
+        default:
+          return '["value1"]';
+      }
     case 'object':
       return '{"key":"value"}';
     default: {

tests/generate-cli-helpers.test.ts

@@ -100,6 +100,9 @@ describe('generate helpers', () => {
     expect(buildExampleValue('itemId', 'string', undefined, undefined)).toBe('example-id');
     expect(buildExampleValue('mode', 'string', ['fast'], undefined)).toBe('fast');
     expect(buildExampleValue('fields', 'object', undefined, undefined)).toBe('{"key":"value"}');
+    expect(buildExampleValue('scores', 'array', undefined, undefined, 'number')).toBe('1,2');
+    expect(buildExampleValue('flags', 'array', undefined, undefined, 'boolean')).toBe('true,false');
+    expect(buildExampleValue('records', 'array', undefined, undefined, 'object')).toBe('[{"key":"value"}]');
 
     expect(inferType({ type: 'boolean' })).toBe('boolean');
     expect(inferType({ type: 'integer' })).toBe('number');
@@ -143,6 +146,61 @@ describe('generate helpers', () => {
         placeholder: '<items>',
       })
     ).toBe('["foo", "bar"]');
+    expect(
+      pickExampleLiteral({
+        type: 'array',
+        arrayItemType: 'number',
+        exampleValue: '1,2',
+        property: 'scores',
+        cliName: 'scores',
+        required: true,
+        placeholder: '<scores>',
+      })
+    ).toBe('[1, 2]');
+    expect(
+      pickExampleLiteral({
+        type: 'array',
+        arrayItemType: 'boolean',
+        exampleValue: 'true,false',
+        property: 'flags',
+        cliName: 'flags',
+        required: true,
+        placeholder: '<flags>',
+      })
+    ).toBe('[true, false]');
+    expect(
+      pickExampleLiteral({
+        type: 'array',
+        arrayItemType: 'object',
+        exampleValue: '[{"key":"value"}]',
+        property: 'records',
+        cliName: 'records',
+        required: true,
+        placeholder: '<records>',
+      })
+    ).toBe('[{"key":"value"}]');
+    expect(
+      pickExampleLiteral({
+        type: 'array',
+        arrayItemType: 'number',
+        defaultValue: [3, 5],
+        property: 'scores',
+        cliName: 'scores',
+        required: true,
+        placeholder: '<scores>',
+      })
+    ).toBe('[3,5]');
+    expect(
+      pickExampleLiteral({
+        type: 'array',
+        arrayItemType: 'string',
+        enumValues: ['alpha', 'beta'],
+        property: 'labels',
+        cliName: 'labels',
+        required: true,
+        placeholder: '<labels>',
+      })
+    ).toBe('["alpha"]');
     expect(
       pickExampleLiteral({
         type: 'string',
@@ -162,6 +220,36 @@ describe('generate helpers', () => {
         placeholder: '<issue-id>',
       })
     ).toBe('"example-id"');
+    expect(
+      buildFallbackLiteral({
+        type: 'array',
+        arrayItemType: 'number',
+        property: 'scores',
+        cliName: 'scores',
+        required: false,
+        placeholder: '<scores>',
+      })
+    ).toBe('[1]');
+    expect(
+      buildFallbackLiteral({
+        type: 'array',
+        arrayItemType: 'boolean',
+        property: 'flags',
+        cliName: 'flags',
+        required: false,
+        placeholder: '<flags>',
+      })
+    ).toBe('[true]');
+    expect(
+      buildFallbackLiteral({
+        type: 'array',
+        arrayItemType: 'object',
+        property: 'records',
+        cliName: 'records',
+        required: false,
+        placeholder: '<records>',
+      })
+    ).toBe('[{"key":"value"}]');
     expect(
       buildFallbackLiteral({
         type: 'array',

tests/list-detail-helpers.test.ts

@@ -150,6 +150,24 @@ describe('formatCallExpressionExample', () => {
     );
     expect(example).toBe('mcporter call \'https://mcp.sentry.dev/mcp?agent=1.use_sentry(request: "value")\'');
   });
+
+  it('keeps array examples consistent with their item types', () => {
+    const example = formatCallExpressionExample('fixture', 'array_probe', [
+      baseOption({ property: 'scores', type: 'array', arrayItemType: 'number', exampleValue: '1,2' }),
+      baseOption({ property: 'flags', type: 'array', arrayItemType: 'boolean', exampleValue: 'true,false' }),
+      baseOption({
+        property: 'records',
+        type: 'array',
+        arrayItemType: 'object',
+        exampleValue: '[{"key":"value"}]',
+      }),
+      baseOption({ property: 'names', type: 'array', arrayItemType: 'string', exampleValue: 'value1,value2' }),
+    ]);
+
+    expect(example).toBe(
+      'mcporter call fixture.array_probe(scores: [1, 2], flags: [true, false], records: [{"key":"value"}], names: ["value1", "value2"])'
+    );
+  });
 });
 
 describe('formatExampleBlock', () => {