feat: enable telemetry for embedded AI agents (#667)

Enable input/output recording in Vercel AI integration and add
experimental telemetry to callEmbeddedAgent for better observability of
AI-powered tool calls.

Co-authored-by: Claude <noreply@anthropic.com>

Author: dcramer

packages/mcp-core/src/internal/agents/callEmbeddedAgent.ts

@@ -45,6 +45,10 @@ export async function callEmbeddedAgent<
     maxSteps: 5,
     temperature: 1, // GPT-5 only supports temperature of 1
     experimental_output: Output.object({ schema }),
+    experimental_telemetry: {
+      isEnabled: true,
+      functionId: "callEmbeddedAgent",
+    },
     // Disable strict schema validation for both output and tool parameter schemas.
     //
     // OpenAI's structured outputs have limitations: