Add dedicated tracing for MCP resources (#11569)

* Initial plan

* feat: Add separate tracing for MCP resources

Co-authored-by: tommoor <380914+tommoor@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: tommoor <380914+tommoor@users.noreply.github.com>

server/tools/collections.ts

@@ -17,6 +17,7 @@ import {
   buildAPIContext,
   pathToUrl,
   withTracing,
+  withResourceTracing,
 } from "./util";
 
 /**
@@ -128,7 +129,7 @@ export function collectionTools(server: McpServer, scopes: string[]) {
           "Fetches the details of a collection by its ID, including its document structure.",
         mimeType: "application/json",
       },
-      withTracing("get_collection", async (uri, variables, extra) => {
+      withResourceTracing("get_collection", async (uri, variables, extra) => {
         try {
           const { id } = variables;
           const user = getActorFromContext(extra);

server/tools/documents.ts

@@ -25,6 +25,7 @@ import {
   getActorFromContext,
   pathToUrl,
   withTracing,
+  withResourceTracing,
 } from "./util";
 import { TextEditMode } from "@shared/types";
 
@@ -45,7 +46,7 @@ export function documentTools(server: McpServer, scopes: string[]) {
         description: "Fetches the content of a document by its ID.",
         mimeType: "text/markdown",
       },
-      withTracing("get_document", async (uri, variables, extra) => {
+      withResourceTracing("get_document", async (uri, variables, extra) => {
         try {
           const { id } = variables;
           const user = getActorFromContext(extra);

server/tools/users.ts

@@ -11,7 +11,7 @@ import { User, Team } from "@server/models";
 import { authorize, can } from "@server/policies";
 import { presentUser } from "@server/presenters";
 import AuthenticationHelper from "@shared/helpers/AuthenticationHelper";
-import { error, success, getActorFromContext, withTracing } from "./util";
+import { error, success, getActorFromContext, withTracing, withResourceTracing } from "./util";
 
 /**
  * Resolves a user identifier to a User model instance. Accepts special
@@ -50,7 +50,7 @@ export function userTools(server: McpServer, scopes: string[]) {
           'Fetches a user by their ID. Use "current_user" as the ID to get the currently authenticated user.',
         mimeType: "application/json",
       },
-      withTracing("get_user", async (uri, variables, extra) => {
+      withResourceTracing("get_user", async (uri, variables, extra) => {
         try {
           const { id } = variables;
           const actor = getActorFromContext(extra);

server/tools/util.ts

@@ -76,11 +76,11 @@ export function error(err: unknown): CallToolResult {
 }
 
 /**
- * Wraps an MCP tool or resource handler with Datadog tracing. Each invocation
- * creates a span under the `outline-mcp` service with the tool name as the
- * resource, and tags it with the acting user and team IDs.
+ * Wraps an MCP tool handler with Datadog tracing. Each invocation creates a
+ * span under the `outline-mcp` service with the tool name as the resource,
+ * and tags it with the acting user and team IDs.
  *
- * @param toolName - the name of the MCP tool or resource being traced.
+ * @param toolName - the name of the MCP tool being traced.
  * @param handler - the handler function to wrap.
  * @returns the wrapped handler with tracing enabled.
  */
@@ -106,6 +106,37 @@ export function withTracing<F extends (...args: any[]) => any>(
   } as F);
 }
 
+/**
+ * Wraps an MCP resource handler with Datadog tracing. Each invocation creates
+ * a span under the `outline-mcp` service with the resource name, and tags it
+ * with the acting user and team IDs.
+ *
+ * @param resourceName - the name of the MCP resource being traced.
+ * @param handler - the handler function to wrap.
+ * @returns the wrapped handler with tracing enabled.
+ */
+export function withResourceTracing<F extends (...args: any[]) => any>(
+  resourceName: string,
+  handler: F
+): F {
+  return traceFunction({
+    serviceName: "mcp",
+    spanName: "resource",
+    resourceName: resourceName,
+  })(function tracedHandler(this: any, ...args: any[]) {
+    const context = args[args.length - 1];
+    const user = getActorFromContext(context);
+    if (user) {
+      addTags({
+        "mcp.resource": resourceName,
+        "request.userId": user.id,
+        "request.teamId": user.teamId,
+      });
+    }
+    return handler.apply(this, args);
+  } as F);
+}
+
 /**
  * Utility function to construct a URL by joining a team URL with a path segment.
  *