fix(core): Stringify available tools sent from vercelai

.size-limit.js

@@ -240,7 +240,7 @@ module.exports = [
     import: createImport('init'),
     ignore: [...builtinModules, ...nodePrefixedBuiltinModules],
     gzip: true,
-    limit: '158 KB',
+    limit: '159 KB',
   },
   {
     name: '@sentry/node - without tracing',

dev-packages/node-integration-tests/suites/tracing/vercelai/test.ts

@@ -197,6 +197,9 @@ describe('Vercel AI integration', () => {
     ]),
   };
 
+  const EXPECTED_AVAILABLE_TOOLS_JSON =
+    '[{"type":"function","name":"getWeather","parameters":{"type":"object","properties":{"location":{"type":"string"}},"required":["location"],"additionalProperties":false,"$schema":"http://json-schema.org/draft-07/schema#"}}]';
+
   const EXPECTED_TRANSACTION_DEFAULT_PII_TRUE = {
     transaction: 'main',
     spans: expect.arrayContaining([
@@ -358,7 +361,7 @@ describe('Vercel AI integration', () => {
           'vercel.ai.prompt.format': expect.any(String),
           'gen_ai.request.messages': expect.any(String),
           'vercel.ai.prompt.toolChoice': expect.any(String),
-          'gen_ai.request.available_tools': expect.any(Array),
+          'gen_ai.request.available_tools': EXPECTED_AVAILABLE_TOOLS_JSON,
           'vercel.ai.response.finishReason': 'tool-calls',
           'vercel.ai.response.id': expect.any(String),
           'vercel.ai.response.model': 'mock-model-id',

dev-packages/node-integration-tests/suites/tracing/vercelai/v5/test.ts

@@ -193,6 +193,9 @@ describe('Vercel AI integration (V5)', () => {
     ]),
   };
 
+  const EXPECTED_AVAILABLE_TOOLS_JSON =
+    '[{"type":"function","name":"getWeather","inputSchema":{"$schema":"http://json-schema.org/draft-07/schema#","type":"object","properties":{"location":{"type":"string"}},"required":["location"],"additionalProperties":false}}]';
+
   const EXPECTED_TRANSACTION_DEFAULT_PII_TRUE = {
     transaction: 'main',
     spans: expect.arrayContaining([
@@ -348,7 +351,7 @@ describe('Vercel AI integration (V5)', () => {
           'vercel.ai.pipeline.name': 'generateText.doGenerate',
           'gen_ai.request.messages': expect.any(String),
           'vercel.ai.prompt.toolChoice': expect.any(String),
-          'gen_ai.request.available_tools': expect.any(Array),
+          'gen_ai.request.available_tools': EXPECTED_AVAILABLE_TOOLS_JSON,
           'vercel.ai.response.finishReason': 'tool-calls',
           'vercel.ai.response.id': expect.any(String),
           'vercel.ai.response.model': 'mock-model-id',

packages/core/src/tracing/vercel-ai/index.ts

@@ -10,7 +10,7 @@ import {
 import { getTruncatedJsonString } from '../ai/utils';
 import { toolCallSpanMap } from './constants';
 import type { TokenSummary } from './types';
-import { accumulateTokensForParent, applyAccumulatedTokens } from './utils';
+import { accumulateTokensForParent, applyAccumulatedTokens, convertAvailableToolsToJsonString } from './utils';
 import type { ProviderMetadata } from './vercel-ai-attributes';
 import {
   AI_MODEL_ID_ATTRIBUTE,
@@ -123,6 +123,13 @@ function processEndedVercelAiSpan(span: SpanJSON): void {
       attributes[GEN_AI_USAGE_OUTPUT_TOKENS_ATTRIBUTE] + attributes[GEN_AI_USAGE_INPUT_TOKENS_ATTRIBUTE];
   }
 
+  // Convert the available tools array to a JSON string
+  if (attributes[AI_PROMPT_TOOLS_ATTRIBUTE] && Array.isArray(attributes[AI_PROMPT_TOOLS_ATTRIBUTE])) {
+    attributes[AI_PROMPT_TOOLS_ATTRIBUTE] = convertAvailableToolsToJsonString(
+      attributes[AI_PROMPT_TOOLS_ATTRIBUTE] as unknown[],
+    );
+  }
+
   // Rename AI SDK attributes to standardized gen_ai attributes
   renameAttributeKey(attributes, AI_PROMPT_MESSAGES_ATTRIBUTE, 'gen_ai.request.messages');
   renameAttributeKey(attributes, AI_RESPONSE_TEXT_ATTRIBUTE, 'gen_ai.response.text');

packages/core/src/tracing/vercel-ai/utils.ts

@@ -70,3 +70,20 @@ export function _INTERNAL_getSpanForToolCallId(toolCallId: string): Span | undef
 export function _INTERNAL_cleanupToolCallSpan(toolCallId: string): void {
   toolCallSpanMap.delete(toolCallId);
 }
+
+/**
+ * Convert an array of tool strings to a JSON string
+ */
+export function convertAvailableToolsToJsonString(tools: unknown[]): string {
+  const toolObjects = tools.map(tool => {
+    if (typeof tool === 'string') {
+      try {
+        return JSON.parse(tool);
+      } catch {
+        return tool;
+      }
+    }
+    return tool;
+  });
+  return JSON.stringify(toolObjects);
+}