# Task ID: 50

**Title:** Implement progressive tool exposure for gated sessions

**Status:** done

**Dependencies:** 48 ✓, 49 ✓

**Priority:** high

**Description:** Modify tools/list behavior to only expose begin_session while gated, and expose all tools plus read_prompts after ungating.

**Details:**

1. Update tools/list handling in `/src/mcplocal/src/router.ts`:
   ```typescript
   async handleToolsList(sessionId: string): Promise<Tool[]> {
     const state = this.getSessionState(sessionId);
     
     if (state.gated) {
       // Only show begin_session while gated
       return [this.getBeginSessionTool()];
     }
     
     // After ungating: all upstream tools + read_prompts
     const upstreamTools = await this.discoverTools();
     return [...upstreamTools, this.getReadPromptsTool()];
   }
   ```

2. Block direct tool calls while gated:
   ```typescript
   async handleToolCall(sessionId: string, toolName: string, args: any): Promise<any> {
     const state = this.getSessionState(sessionId);
     
     if (state.gated && toolName !== 'begin_session') {
       // Intercept: extract keywords, match prompts, inject briefing
       return this.handleInterceptedCall(sessionId, toolName, args);
     }
     
     // Normal routing
     return this.routeToolCall(toolName, args);
   }
   ```

3. Ensure notifications/tools/list_changed is sent after ungating

**Test Strategy:**

- Unit test: tools/list while gated returns only begin_session
- Unit test: tools/list after ungating returns all tools + read_prompts
- Unit test: begin_session not visible after ungating
- Unit test: Tool call while gated (not begin_session) triggers intercept
- Unit test: Tool call after ungating routes normally
- Unit test: notifications/tools/list_changed sent on ungate