[Bug] MCP tools loaded upfront despite tengu_mcp_tool_search flag enabled

Bug Description

• My context shows 14.2% MCP usage (above 10% threshold)
• tengu_mcp_tool_search feature flag is true
• MCP tools are still loaded upfront
• Using v2.1.7 with Opus model

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.1.7
• Feedback ID: 666ec9d7-a504-4d2d-85f7-dc30a507191b

Errors

[{"error":"Error: Plugin MCP server error - mcp-config-invalid: MCP server github invalid: Missing environment variables: GITHUB_PERSONAL_ACCESS_TOKEN\n    at cEA (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3003:23303)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at async hP0.<anonymous> (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:5222:708)\n    at async hP0.parseAsync (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4718:4156)\n    at async J_7 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:5252:1637)\n    at async G_7 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:5175:1561)\n    at async D_7 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:5254:5850)","timestamp":"2026-01-15T01:10:56.218Z"},{"error":"Error: Plugin MCP server error - mcp-config-invalid: MCP server github invalid: Missing environment variables: GITHUB_PERSONAL_ACCESS_TOKEN\n    at cEA (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3003:23303)\n    at processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at runNextTicks (node:internal/process/task_queues:69:3)\n    at process.processImmediate (node:internal/timers:479:9)\n    at async K (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3452:13161)","timestamp":"2026-01-15T01:10:56.569Z"},{"error":"Error: Plugin MCP server error - mcp-config-invalid: MCP server github invalid: Missing environment variables: GITHUB_PERSONAL_ACCESS_TOKEN\n    at cEA (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3003:23303)\n    at processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at runNextTicks (node:internal/process/task_queues:69:3)\n    at process.processImmediate (node:internal/timers:479:9)\n    at async V (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3452:13677)","timestamp":"2026-01-15T01:10:56.569Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"prompt is too long: 202168 tokens > 200000 maximum\"},\"request_id\":\"req_011CX8H5ycnpzwuQ2RJ2zypx\"}\n    at D9.generate (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:491:33583)\n    at hP.makeStatusError (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:914:2195)\n    at hP.makeRequest (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:914:5420)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at async BJ9.v51.model (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4371:6288)\n    at async v51 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1064:97940)\n    at async BJ9 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4371:6442)\n    at async file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4369:3557\n    at async LZ0 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1065:1998)\n    at async Pd (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4369:3528)","timestamp":"2026-01-15T01:14:50.736Z"},{"error":"Error: EISDIR: illegal operation on a directory, read\n    at Module.readFileSync (node:fs:443:20)\n    at file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:9:464\n    at MW (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:8:34212)\n    at Object.readFileSync (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:9:433)\n    at L12 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4697:23898)\n    at Object.call (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1676:942)\n    at b77 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3141:17896)","timestamp":"2026-01-15T01:14:57.554Z"},{"error":"MaxFileReadTokenExceededError: File content (77437 tokens) exceeds maximum allowed tokens (25000). Please use offset and limit parameters to read specific portions of the file, or use the GrepTool to search for specific content.\n    at w12 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1667:13298)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at async Object.call (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1676:996)\n    at async file:///opt/homebrew/lib/node_modules/@anthropic-ai/clau

Note: Error logs were truncated.