gemini_reason

Instructions

Implementation Reference

• src/handlers/unified-gemini.js:282-336 (handler)

  Core handler function that executes the gemini_reason tool: validates 'problem' input, selects Gemini model, builds reasoning prompt, calls Gemini API, formats and returns response.

  /**
   * Handle Gemini reasoning request
   * @param {Object} request - MCP request
   * @returns {Promise<Object>} - MCP response
   */
  function handleReason(request) {
      return __awaiter(this, void 0, void 0, function () {
          var _a, problem, file_path, model_id, _b, show_steps, modelId, internalRequest, response, error_3;
          return __generator(this, function (_c) {
              switch (_c.label) {
                  case 0:
                      _c.trys.push([0, 3, , 4]);
                      // Validate required parameters
                      if (!request.params.arguments || typeof request.params.arguments.problem !== 'string') {
                          throw new types_js_1.McpError(types_js_1.ErrorCode.InvalidParams, 'Problem parameter is required and must be a string');
                      }
                      _a = request.params.arguments, problem = _a.problem, file_path = _a.file_path, model_id = _a.model_id, _b = _a.show_steps, show_steps = _b === void 0 ? true : _b;
                      modelId = model_id || model_selector_js_1.MODELS.FLASH_THINKING;
                      return [4 /*yield*/, (0, request_builder_js_1.buildReasoningRequest)({
                              problem: problem,
                              modelId: modelId,
                              filePath: file_path,
                              showSteps: show_steps
                          })];
                  case 1:
                      internalRequest = _c.sent();
                      return [4 /*yield*/, executeRequest(modelId, internalRequest)];
                  case 2:
                      response = _c.sent();
                      // Format response
                      return [2 /*return*/, formatResponse(response, modelId, {
                              operation: exports.TOOL_NAMES.GEM_REASON,
                              withFile: !!file_path,
                              showSteps: show_steps
                          })];
                  case 3:
                      error_3 = _c.sent();
                      console.error('Error in reasoning handler:', error_3);
                      if (error_3 instanceof types_js_1.McpError) {
                          throw error_3;
                      }
                      return [2 /*return*/, {
                              content: [
                                  {
                                      type: 'text',
                                      text: "Error: ".concat(error_3 instanceof Error ? error_3.message : 'Unknown error')
                                  }
                              ],
                              isError: true
                          }];
                  case 4: return [2 /*return*/];
              }
          });
      });
  }

• src/index.ts:92-117 (schema)

  Input schema and metadata for the gemini_reason tool, registered in the MCP tools/list endpoint.

    name: TOOL_NAMES.GEM_REASON,
    description: 'Solves complex problems with step-by-step reasoning using Gemini 2.0 Flash Thinking. Best for math and science problems, coding challenges, and tasks requiring transparent reasoning process.',
    inputSchema: {
      type: 'object',
      properties: {
        problem: {
          type: 'string',
          description: 'The complex problem or question to solve'
        },
        file_path: {
          type: 'string',
          description: 'Optional file path to include with the problem'
        },
        show_steps: {
          type: 'boolean',
          description: 'Whether to show detailed reasoning steps (default: false)',
          default: false
        },
        model_id: {
          type: 'string',
          description: 'Optional model ID override (advanced users only)'
        }
      },
      required: ['problem'],
    },
  },

• src/index.ts:206-228 (registration)

  Tool dispatch switch in MCP CallToolRequest handler that routes 'gemini_reason' and TOOL_NAMES.GEM_REASON calls to handleReason function.

  switch (request.params.name) {
    case TOOL_NAMES.GEM_SEARCH:
      // Use the alternative direct search handler that works with Flash models
      return await handleDirectSearchAlt(request);
    case TOOL_NAMES.GEM_REASON:
      return await handleReason(request);
    case TOOL_NAMES.GEM_CODE:
      return await handleCode(request);
    case TOOL_NAMES.GEM_FILEOPS:
      return await handleFileops(request);
    // Support legacy tool names for backward compatibility
    case 'gemini_search':
      // Use the alternative direct search handler that works with Flash models
      return await handleDirectSearchAlt(request);
    case 'gemini_reason':
      return await handleReason(request);
    default:
      console.error(`Unknown tool requested: ${request.params.name}`);
      throw new McpError(
        ErrorCode.MethodNotFound,
        `Unknown tool: ${request.params.name}. Available tools: gemini_search, gemini_reason, gemini_code, gemini_fileops`
      );
  }

• src/config/constants.ts:105-117 (registration)

  TOOL_NAMES constant defining GEM_REASON: 'gemini_reason' used for tool name references throughout the codebase.

  export const TOOL_NAMES = {
    // New specialized toolset
    GEM_SEARCH: 'gemini_search',    // For search-enabled queries (Gemini 2.0 Flash)
    GEM_REASON: 'gemini_reason',    // For complex reasoning (Gemini 2.5 Flash/Pro)
    GEM_CODE: 'gemini_code',        // For coding tasks (Gemini 2.5 Pro)
    GEM_FILEOPS: 'gemini_fileops',  // For file operations (Gemini 2.0 Flash-Lite/1.5 Pro)
  
    // Legacy names for backward compatibility - only keeping what's needed
    SEARCH: 'gemini_search',
    REASON: 'gemini_reason',
    ANALYZE_FILE: 'gemini_analyze',
    RAPID_SEARCH: 'gemini_search'
  };