feat: add excludeResponse parameter to reduce token usage (#136)

Added an optional excludeResponse parameter to all MCP tools that allows
excluding the full response body from Microsoft Graph API and only
returning a success/failure indication.

This is useful for operations where only the outcome matters (success or
failure) and the response data is not needed, significantly reducing
token usage in MCP responses.

Changes:
- Added excludeResponse parameter to all tool schemas (default: false)
- Updated GraphRequestOptions interface to include excludeResponse
- Modified formatJsonResponse to return minimal response when enabled
- Added error handling to return { success: false } for failures

Behavior:
- excludeResponse=false (default): Returns full response as before
- excludeResponse=true (success): Returns { "success": true }
- excludeResponse=true (error): Returns { "success": false } with isError: true

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude <[email protected]>

Author: steffen-heil-secforge

src/graph-client.ts

@@ -8,6 +8,7 @@ interface GraphRequestOptions {
   body?: string;
   rawResponse?: boolean;
   includeHeaders?: boolean;
+  excludeResponse?: boolean;
   accessToken?: string;
   refreshToken?: string;
 
@@ -164,7 +165,7 @@ class GraphClient {
       // Use new OAuth-aware request method
       const result = await this.makeRequest(endpoint, options);
 
-      return this.formatJsonResponse(result, options.rawResponse);
+      return this.formatJsonResponse(result, options.rawResponse, options.excludeResponse);
     } catch (error) {
       logger.error(`Error in Graph API request: ${error}`);
       return {
@@ -174,7 +175,14 @@ class GraphClient {
     }
   }
 
-  formatJsonResponse(data: unknown, rawResponse = false): McpResponse {
+  formatJsonResponse(data: unknown, rawResponse = false, excludeResponse = false): McpResponse {
+    // If excludeResponse is true, only return success indication
+    if (excludeResponse) {
+      return {
+        content: [{ type: 'text', text: JSON.stringify({ success: true }) }],
+      };
+    }
+
     // Handle the case where data includes headers metadata
     if (data && typeof data === 'object' && '_headers' in data) {
       const responseData = data as {

src/graph-tools.ts

@@ -130,6 +130,12 @@ export function registerGraphTools(
       .describe('Include response headers (including ETag) in the response metadata')
       .optional();
 
+    // Add excludeResponse parameter to only return success/failure indication
+    paramSchema['excludeResponse'] = z
+      .boolean()
+      .describe('Exclude the full response body and only return success or failure indication')
+      .optional();
+
     server.tool(
       tool.alias,
       tool.description || `Execute ${tool.method.toUpperCase()} request to ${tool.path}`,
@@ -161,6 +167,11 @@ export function registerGraphTools(
               continue;
             }
 
+            // Skip excludeResponse control parameter - it's not part of the Microsoft Graph API
+            if (paramName === 'excludeResponse') {
+              continue;
+            }
+
             // Ok, so, MCP clients (such as claude code) doesn't support $ in parameter names,
             // and others might not support __, so we strip them in hack.ts and restore them here
             const odataParams = [
@@ -236,6 +247,7 @@ export function registerGraphTools(
             body?: string;
             rawResponse?: boolean;
             includeHeaders?: boolean;
+            excludeResponse?: boolean;
           } = {
             method: tool.method.toUpperCase(),
             headers,
@@ -258,6 +270,11 @@ export function registerGraphTools(
             options.includeHeaders = true;
           }
 
+          // Set excludeResponse if requested
+          if (params.excludeResponse === true) {
+            options.excludeResponse = true;
+          }
+
           logger.info(`Making graph request to ${path} with options: ${JSON.stringify(options)}`);
           let response = await graphClient.graphRequest(path, options);