Local MCP servers connect successfully but tools are not surfaced to the AI model

Version

2.1.119

Description

Local MCP servers configured in ~/.claude/settings.json start, connect, and list their tools successfully (confirmed via logs), but those tools are never made available to the AI model in the session. Only the built-in claude.ai cloud connectors appear as callable tools.

Affected servers: aha-mcp, Control Chrome (both stdio-based via npx)

Steps to Reproduce

1. Add an MCP server to ~/.claude/settings.json under mcpServers
2. Restart Claude Code
3. Check ~/Library/Logs/Claude/mcp.log — server connects and tools/list returns tools successfully
4. Ask Claude to use one of the tools — Claude reports the tools are not available

Expected Behavior

Tools from local MCP servers are available to the AI model, the same as the built-in claude.ai cloud connectors.

Actual Behavior

Tools connect and list successfully in logs but are never passed to the model. ListMcpResourcesTool also does not recognize the local server by name:

Error: Server "aha-mcp" not found. Available servers: claude.ai Microsoft 365, claude.ai Notion, claude.ai monday.com, claude.ai Linear, claude.ai Intercom, claude.ai HubSpot, claude.ai Figma, claude.ai Canva, claude.ai Box, claude.ai Atlassian, claude.ai Asana

Log Evidence

From ~/Library/Logs/Claude/mcp.log:

[aha-mcp] Server started and connected successfully
[aha-mcp] Message from client: {"method":"initialize",...}
[aha-mcp] Message from server: {"result":{"protocolVersion":"2025-11-25","capabilities":{"tools":{}},"serverInfo":{"name":"aha-mcp","version":"1.1.0"}}}
[aha-mcp] Message from client: {"method":"tools/list",...}
[aha-mcp] Message from server: {"result":{"tools":[{"name":"get_record",...},{"name":"get_page",...},{"name":"search_documents",...}]}}

Server initializes → tools/list returns tools successfully → tools are silently dropped and never passed to the model.

Platform

• macOS Darwin 25.2.0 (arm64)
• Claude Code 2.1.119