# Task ID: 51

**Title:** Implement keyword extraction from tool calls

**Status:** done

**Dependencies:** None

**Priority:** medium

**Description:** Create a service that extracts keywords from tool names and arguments for the intercept fallback path when clients skip begin_session.

**Details:**

1. Create `/src/mcplocal/src/services/keyword-extractor.service.ts`:
   ```typescript
   export class KeywordExtractorService {
     extractKeywords(toolName: string, args: Record<string, any>): string[] {
       const keywords: string[] = [];
       
       // Extract from tool name (split on / and -)
       // e.g., "home-assistant/get_entities" -> ["home", "assistant", "get", "entities"]
       keywords.push(...this.extractFromName(toolName));
       
       // Extract from argument values
       // e.g., { domain: "light", entity_id: "light.kitchen" } -> ["light", "kitchen"]
       keywords.push(...this.extractFromArgs(args));
       
       // Deduplicate and sanitize
       return [...new Set(keywords.map(k => this.sanitize(k)))];
     }
     
     private sanitize(keyword: string): string {
       // Remove special characters, lowercase, limit length
       return keyword.toLowerCase().replace(/[^a-z0-9]/g, '').slice(0, 50);
     }
   }
   ```

2. Handle various argument types: strings, arrays, nested objects

3. Prevent injection by sanitizing extracted keywords

**Test Strategy:**

- Unit test: Extracts keywords from tool name with /
- Unit test: Extracts keywords from tool name with -
- Unit test: Extracts keywords from string argument values
- Unit test: Extracts keywords from array argument values
- Unit test: Handles nested object arguments
- Unit test: Sanitizes special characters
- Unit test: Deduplicates keywords
- Unit test: Handles empty arguments
- Unit test: Limits keyword length to prevent abuse