suggest_improvements
Read-onlyIdempotent
Analyze code to suggest targeted improvements for performance, readability, maintainability, accessibility, or type-safety based on specified priority levels.
Instructions
개선|더 좋게|리팩토링|improve|make better|refactor|optimize|enhance code - Suggest improvements
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| code | Yes | Code to analyze | |
| focus | No | Focus area | |
| priority | No | Priority level |
Implementation Reference
- The primary handler function implementing the tool logic: analyzes input code based on focus (performance, readability, etc.) and priority, generates suggestions with categories, issues, fixes, and returns a structured result with summary and top suggestions.
export async function suggestImprovements(args: { code: string; focus?: string; priority?: string }): Promise<ToolResult> { const { code, focus = 'maintainability', priority = 'medium' } = args; const suggestions = []; const codeLines = code.split('\n'); const codeLength = codeLines.length; // Performance improvements if (focus === 'performance' || focus === 'all') { // Check for inefficient loops if (code.includes('for') && code.includes('length')) { suggestions.push({ category: 'performance', priority: 'high', issue: 'Potential inefficient loop accessing .length property', suggestion: 'Cache array length in a variable before the loop', example: 'const len = array.length; for (let i = 0; i < len; i++)' }); } // Check for React performance issues if (code.includes('React') || code.includes('jsx') || code.includes('tsx')) { if (!code.includes('memo') && !code.includes('useMemo') && !code.includes('useCallback')) { suggestions.push({ category: 'performance', priority: 'medium', issue: 'Missing React performance optimizations', suggestion: 'Consider using React.memo, useMemo, or useCallback', example: 'const Component = React.memo(() => { ... })' }); } if (code.includes('map') && code.includes('return')) { suggestions.push({ category: 'performance', priority: 'medium', issue: 'Ensure unique keys in map functions', suggestion: 'Use unique and stable keys for list items', example: 'items.map(item => <div key={item.id}>{item.name}</div>)' }); } } // Check for expensive operations if (code.includes('JSON.parse') || code.includes('JSON.stringify')) { suggestions.push({ category: 'performance', priority: 'medium', issue: 'JSON operations can be expensive', suggestion: 'Consider memoizing JSON operations or using alternatives', example: 'const memoizedParse = useMemo(() => JSON.parse(data), [data])' }); } } // Readability improvements if (focus === 'readability' || focus === 'all') { // Check for long functions if (codeLength > 20) { suggestions.push({ category: 'readability', priority: 'high', issue: `Function is too long (${codeLength} lines)`, suggestion: 'Break down into smaller, focused functions', example: 'Extract logical groups into separate functions' }); } // Check for deep nesting let maxNesting = 0; let currentNesting = 0; for (const line of codeLines) { const braceCount = (line.match(/\{/g) || []).length - (line.match(/\}/g) || []).length; currentNesting += braceCount; maxNesting = Math.max(maxNesting, currentNesting); } if (maxNesting > 3) { suggestions.push({ category: 'readability', priority: 'high', issue: `Deep nesting detected (${maxNesting} levels)`, suggestion: 'Use early returns or guard clauses to reduce nesting', example: 'if (!condition) return; // instead of wrapping in else' }); } // Check for magic numbers const magicNumbers = code.match(/\b\d{2,}\b/g) || []; if (magicNumbers.length > 0) { suggestions.push({ category: 'readability', priority: 'medium', issue: 'Magic numbers found in code', suggestion: 'Extract numbers into named constants', example: 'const MAX_RETRY_COUNT = 3; // instead of using 3 directly' }); } // Check for unclear variable names const shortVars = code.match(/\b[a-z]\b/g) || []; if (shortVars.length > 2) { suggestions.push({ category: 'readability', priority: 'medium', issue: 'Single letter variable names detected', suggestion: 'Use descriptive variable names', example: 'const userIndex = 0; // instead of i = 0' }); } } // Maintainability improvements if (focus === 'maintainability' || focus === 'all') { // Check for error handling const hasAsyncCode = code.includes('async') || code.includes('await') || code.includes('Promise'); const hasErrorHandling = code.includes('try') || code.includes('catch') || code.includes('throw'); if (hasAsyncCode && !hasErrorHandling) { suggestions.push({ category: 'maintainability', priority: 'high', issue: 'Async code without error handling', suggestion: 'Add try-catch blocks for async operations', example: 'try { await asyncOperation(); } catch (error) { handleError(error); }' }); } // Check for code duplication const lines = codeLines.map(line => line.trim()).filter(line => line.length > 5); const duplicateLines = lines.filter((line, index) => lines.indexOf(line) !== index); if (duplicateLines.length > 0) { suggestions.push({ category: 'maintainability', priority: 'medium', issue: 'Potential code duplication detected', suggestion: 'Extract common code into reusable functions', example: 'Create utility functions for repeated logic' }); } // Check for comments const commentLines = code.match(/\/\*[\s\S]*?\*\/|\/\/.*$/gm) || []; const commentRatio = commentLines.length / codeLines.length; if (commentRatio < 0.1 && codeLength > 10) { suggestions.push({ category: 'maintainability', priority: 'low', issue: 'Low comment-to-code ratio', suggestion: 'Add comments explaining complex logic', example: '// Validate user input before processing' }); } } // Type safety improvements if (focus === 'type-safety' || focus === 'all') { // Check for any types if (code.includes('any')) { suggestions.push({ category: 'type-safety', priority: 'high', issue: 'Using "any" type reduces type safety', suggestion: 'Use specific types or interfaces', example: 'interface User { id: string; name: string; }' }); } // Check for loose equality if (code.includes('== ') || code.includes('!= ')) { suggestions.push({ category: 'type-safety', priority: 'medium', issue: 'Loose equality operators found', suggestion: 'Use strict equality operators', example: 'Use === and !== instead of == and !=' }); } // Check for missing return types const functions = code.match(/function\s+\w+\([^)]*\)/g) || []; const functionsWithReturnType = code.match(/function\s+\w+\([^)]*\):\s*\w+/g) || []; if (functions.length > functionsWithReturnType.length) { suggestions.push({ category: 'type-safety', priority: 'medium', issue: 'Functions missing explicit return types', suggestion: 'Add return type annotations', example: 'function getName(): string { return "name"; }' }); } } // Accessibility improvements if (focus === 'accessibility' || focus === 'all') { // Check for missing alt text if (code.includes('<img') && !code.includes('alt=')) { suggestions.push({ category: 'accessibility', priority: 'high', issue: 'Images without alt text', suggestion: 'Add descriptive alt text to images', example: '<img src="..." alt="Description of image" />' }); } // Check for missing ARIA labels if (code.includes('button') && !code.includes('aria-label') && !code.includes('aria-describedby')) { suggestions.push({ category: 'accessibility', priority: 'medium', issue: 'Interactive elements may need ARIA labels', suggestion: 'Add ARIA labels for screen readers', example: '<button aria-label="Close dialog">×</button>' }); } // Check for form labels if (code.includes('<input') && !code.includes('label')) { suggestions.push({ category: 'accessibility', priority: 'high', issue: 'Form inputs without labels', suggestion: 'Associate labels with form controls', example: '<label htmlFor="name">Name:</label><input id="name" />' }); } } // Filter suggestions by priority if specified const filteredSuggestions = priority === 'all' ? suggestions : suggestions.filter(s => s.priority === priority || s.priority === 'critical'); // Sort by priority const priorityOrder = { 'critical': 4, 'high': 3, 'medium': 2, 'low': 1 }; filteredSuggestions.sort((a, b) => (priorityOrder[b.priority as keyof typeof priorityOrder] || 0) - (priorityOrder[a.priority as keyof typeof priorityOrder] || 0)); const improvementResult = { action: 'suggest_improvements', focus, priority, codeStats: { lines: codeLength, functions: (code.match(/function\s+\w+|\w+\s*=\s*\(/g) || []).length, comments: (code.match(/\/\*[\s\S]*?\*\/|\/\/.*$/gm) || []).length }, suggestions: filteredSuggestions, summary: { total: filteredSuggestions.length, critical: filteredSuggestions.filter(s => s.priority === 'critical').length, high: filteredSuggestions.filter(s => s.priority === 'high').length, medium: filteredSuggestions.filter(s => s.priority === 'medium').length, low: filteredSuggestions.filter(s => s.priority === 'low').length }, overallScore: Math.max(0, 100 - (filteredSuggestions.length * 10)), status: 'success' }; const topSuggestions = filteredSuggestions.slice(0, 8); return { content: [{ type: 'text', text: `Focus: ${focus}\nScore: ${improvementResult.overallScore}/100\nSuggestions: ${improvementResult.summary.total} (${improvementResult.summary.critical}C ${improvementResult.summary.high}H ${improvementResult.summary.medium}M ${improvementResult.summary.low}L)\n\n${topSuggestions.map(s => `[${s.priority.toUpperCase()}] ${s.category}\n Issue: ${s.issue}\n Fix: ${s.suggestion}`).join('\n\n')}${filteredSuggestions.length > 8 ? `\n\n... ${filteredSuggestions.length - 8} more suggestions` : ''}` }] }; } - The ToolDefinition providing name, description, input schema (code required, optional focus and priority), and annotations for the MCP tool protocol.
export const suggestImprovementsDefinition: ToolDefinition = { name: 'suggest_improvements', description: '개선|더 좋게|리팩토링|improve|make better|refactor|optimize|enhance code - Suggest improvements', inputSchema: { type: 'object', properties: { code: { type: 'string', description: 'Code to analyze' }, focus: { type: 'string', description: 'Focus area', enum: ['performance', 'readability', 'maintainability', 'accessibility', 'type-safety'] }, priority: { type: 'string', description: 'Priority level', enum: ['critical', 'high', 'medium', 'low'] } }, required: ['code'] }, annotations: { title: 'Suggest Improvements', audience: ['user', 'assistant'], readOnlyHint: true, destructiveHint: false, idempotentHint: true, openWorldHint: false } }; - src/index.ts:123-123 (registration)Addition of the tool definition to the central tools array, enabling discovery via MCP 'tools/list' request.
suggestImprovementsDefinition, - src/index.ts:188-188 (registration)Mapping of tool name to handler function in the toolHandlers registry object, used for dynamic execution dispatch in MCP 'tools/call'.
'suggest_improvements': suggestImprovements, - src/index.ts:64-64 (registration)Import statement bringing in the tool definition and handler implementation for registration.
import { suggestImprovementsDefinition, suggestImprovements } from './tools/convention/suggestImprovements.js';