refactor(WebSearchTool): split Tavily for general search, SearXNG for image search

Tavily lacks image search support, so route search_images requests
to SearXNG unconditionally and use Tavily only for general queries.
Update tests to cover image search and the new routing logic.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/tools/WebSearchTool/WebSearchTool.ts

@@ -167,7 +167,7 @@ function cleanSearchResult(result: any) {
 
 export const WebSearchTool = buildTool({
   name: WEB_SEARCH_TOOL_NAME,
-  description: 'Search the web using local SearXNG or Tavily (when TAVILY_API_KEY is set)',
+  description: 'Search the web — Tavily (when TAVILY_API_KEY is set) for general search, SearXNG for image search',
   shouldDefer: true,
 
   getToolUseSummary,
@@ -245,10 +245,12 @@ export const WebSearchTool = buildTool({
         })
       }
 
-      const useTavily = !!process.env.TAVILY_API_KEY
-      const results = useTavily
-        ? await searchTavily(input.query)
-        : await searchSearXNG(input.query, input.search_images)
+      // Tavily 只做通用搜索，SearXNG 只做图片搜索
+      const results = input.search_images
+        ? await searchSearXNG(input.query, true)
+        : process.env.TAVILY_API_KEY
+          ? await searchTavily(input.query)
+          : await searchSearXNG(input.query, false)
 
       const cleaned = results.map(r => ({
         ...r,

src/tools/WebSearchTool/__tests__/WebSearchTool.test.ts

@@ -190,7 +190,9 @@ describe('WebSearchTool', () => {
       )
 
       expect(result.type).toBe('tool_result')
-      expect(typeof result.content).toBe('string')
+      expect(Array.isArray(result.content)).toBe(true)
+      expect(result.content[0].type).toBe('text')
+      expect(typeof result.content[0].text).toBe('string')
     })
 
     test('should handle empty results', () => {
@@ -205,7 +207,7 @@ describe('WebSearchTool', () => {
         'id'
       )
 
-      expect(result.content).toContain('Results')
+      expect(result.content[0].text).toContain('Results')
     })
   })
 
@@ -223,6 +225,35 @@ describe('WebSearchTool', () => {
       expect(Array.isArray(result.data.results)).toBe(true)
       expect(result.data.durationSeconds).toBeGreaterThan(0)
     }, 60000)
+
+    test('should return image URLs with search_images: true', async () => {
+      const result = await WebSearchTool.call(
+        { query: 'milet 写真', search_images: true },
+        {},
+        () => {},
+        null
+      )
+
+      expect(result).toBeDefined()
+      expect(result.data.query).toBe('milet 写真')
+
+      // Extract and print all image URLs from results
+      const imageUrls: string[] = []
+      for (const r of result.data.results) {
+        if (typeof r === 'string') continue
+        for (const item of r.content) {
+          if (item.image) imageUrls.push(item.image)
+        }
+      }
+
+      console.log(`\nFound ${imageUrls.length} image URLs for "milet 写真":`)
+      for (const url of imageUrls) {
+        console.log(`  ${url}`)
+      }
+
+      // Results may be empty if engines are slow, but the tool should not crash
+      expect(Array.isArray(result.data.results)).toBe(true)
+    }, 60000)
   })
 
   describe('Tavily Integration', () => {
@@ -255,29 +286,29 @@ describe('WebSearchTool', () => {
       expect(Array.isArray(result.data.results)).toBe(true)
     }, 60000)
 
-    test('should use Tavily when TAVILY_API_KEY is set', async () => {
+    test('should return error when Tavily API key is invalid', async () => {
       process.env.TAVILY_API_KEY = 'tvly-test-key'
 
       const result = await WebSearchTool.call(
-        { query: 'test tavily query' },
+        { query: 'typescript' },
         {},
         () => {},
         null
       )
 
-      // With a fake key, Tavily will fail and we should get an error result
       expect(result).toBeDefined()
-      expect(result.data.query).toBe('test tavily query')
+      expect(result.data.query).toBe('typescript')
       expect(Array.isArray(result.data.results)).toBe(true)
-      // The result should contain an error since the API key is invalid
+      // With an invalid Tavily key, searchTavily throws → outer catch returns an error
       const hasError = result.data.results.some(
         r => typeof r === 'string' && r.includes('Error')
       )
       expect(hasError).toBe(true)
     }, 60000)
 
-    test('should include Tavily in description when key is set', () => {
+    test('should mention Tavily and SearXNG in description', () => {
       expect(WebSearchTool.description).toContain('Tavily')
+      expect(WebSearchTool.description).toContain('SearXNG')
     })
   })
 })

src/tools/WebSearchTool/prompt.ts

@@ -6,24 +6,20 @@ export function getWebSearchPrompt(): string {
   const currentMonthYear = getLocalMonthYear()
 
   return `
-- Allows Codev to search the web using a local SearXNG search engine or Tavily cloud search (when TAVILY_API_KEY is configured) and use the results to inform responses
+- Allows Codev to search the web and use results to inform responses
 - Provides up-to-date information for current events, technical documentation, and recent data
 - Returns structured search results including titles, URLs, and snippets
 - Works with all AI providers including local models
 - Designed for high-recall search to support reasoning and retrieval-augmented generation (RAG)
 
-Search Strategy:
-  - Default: Uses SearXNG metasearch engine (aggregates multiple sources)
-  - When TAVILY_API_KEY is set: Uses Tavily cloud search API for high-quality, LLM-optimized results
-  - Results may vary in quality; prioritize relevance and credibility
-  - If results are weak or empty, try rephrasing the query
-  - Prefer more specific queries when possible (add keywords, version numbers, or context)
+Search backends (automatic — no action needed):
+  - **General web search**: Uses Tavily cloud API when TAVILY_API_KEY is set; falls back to SearXNG if not
+  - **Image search** (search_images: true): Always uses SearXNG (Tavily does not support image search)
 
-Image Search (search_images parameter):
+Image Search (search_images: true):
   - Set **search_images: true** to search specifically for images (photos, artworks, screenshots).
     Example: WebSearch(query: "milet 写真", search_images: true)
-  - When search_images is true, results include direct image URLs (img_src) that you can display
-    with ImageShowTool(src: img_src).
+  - Results include direct image URLs (img_src) that you can display with ImageShowTool(src: img_src).
   - Example workflow: WebSearch(query: "...", search_images: true) → pick a result → ImageShowTool(src: img_src)
   - Without search_images: true, this is a general web search and image URLs are NOT available.
   - DO NOT pass article/page URLs to ImageShowTool — it only accepts direct image URLs (.jpg/.png/.gif/.webp).