[bot] Bedrock Converse/ConverseStream requests: toolConfig (tool definitions) never captured in span metadata

Bắt đầu trong braintrust-sdk/src/main/java/dev/braintrust/instrumentation/InstrumentationSemConv.java tại tagBedrockRequest, sau đó kiểm tra BraintrustBedrockInterceptor.java và BraintrustAWSBedrockTest.java. Bổ sung coverage cho việc capture các request Converse và ConverseStream có toolConfig, đồng thời xác minh rằng các định nghĩa tool và chính sách lựa chọn tool xuất hiện trong metadata được capture hoặc input_json.

Summary

InstrumentationSemConv.tagBedrockRequest() extracts inferenceConfig (maxTokens/temperature/topP/stopSequences), system, and messages from the Bedrock Converse/ConverseStream request body, but never reads the top-level toolConfig field. toolConfig carries the tool definitions and tool-choice policy sent to the model — a core, documented part of the Converse API request — and is silently dropped from every Bedrock LLM span's braintrust.metadata/braintrust.input_json, for both streaming and non-streaming calls.

This is a request-side gap and is distinct from issue #85 (which covers the response-side streaming reconstruction dropping tool-use content blocks in TeeingSubscriber/buildConverseJson). Even for non-streaming Converse calls where the response-side tool use is captured correctly by normalizeBedrockMessage(), the request never shows what tools were offered to the model or what tool-choice policy was set.

What is missing

In tagBedrockRequest() (InstrumentationSemConv.java, lines 339-396):

if (requestBody != null) {
    JsonNode requestJson = BraintrustJsonMapper.get().readTree(requestBody);
    if (requestJson.has("inferenceConfig")) { ... }   // handled
    if (requestJson.has("messages")) { ... }           // handled
}

There is no if (requestJson.has("toolConfig")) branch anywhere in this method. The Converse/ConverseStream request body's toolConfig object — containing tools (an array of toolSpec definitions with name/description/inputSchema) and toolChoice (auto/any/{tool: {name}}) — is read from requestBody but never surfaced into metadata or input_json. A trace of a tool-enabled Bedrock call shows the conversation and inference params but gives no visibility into which tools were available or how tool selection was constrained, even though the model's resulting stopReason: "tool_use" and tool call are otherwise correctly displayed.

Braintrust docs status

• Bedrock is listed as a supported provider at https://www.braintrust.dev/docs/integrations/ai-providers: supported
• No Bedrock-specific mention of tool/function-call request metadata capture on Braintrust docs: not_found

Upstream sources

• AWS Bedrock Converse API reference: https://docs.aws.amazon.com/bedrock/latest/APIReference/API_runtime_Converse.html — documents toolConfig as a top-level request field alongside messages, system, inferenceConfig
• AWS Bedrock ConverseStream API reference: https://docs.aws.amazon.com/bedrock/latest/APIReference/API_runtime_ConverseStream.html — same toolConfig request field
• AWS Bedrock tool use guide: https://docs.aws.amazon.com/bedrock/latest/userguide/tool-use.html — describes toolConfig.tools/toolConfig.toolChoice semantics

Local files inspected

• braintrust-sdk/src/main/java/dev/braintrust/instrumentation/InstrumentationSemConv.java — lines 339-396 (tagBedrockRequest: reads inferenceConfig, system, messages; no toolConfig handling anywhere in the method or file)
• braintrust-sdk/instrumentation/aws_bedrock_2_30_0/src/main/java/dev/braintrust/instrumentation/awsbedrock/v2_30_0/BraintrustBedrockInterceptor.java — passes the raw request body through to tagBedrockRequest; no separate toolConfig handling
• braintrust-sdk/instrumentation/aws_bedrock_2_30_0/src/test/java/dev/braintrust/instrumentation/awsbedrock/v2_30_0/BraintrustAWSBedrockTest.java — no test asserts on toolConfig appearing in captured metadata