fix: Remove status field from toolResult for non-claude 3 models in Bedrock model provider

[mehtarac]

Description

Removed the status field from the toolResult block for non claude-3 models in the Bedrock Model provider. This change is motivated by the linked issue. Furthermore, this change is supported by the bedrock documentation where it explicitly states that the status field is only supported in claude 3 models.

Related Issues

#554

Documentation PR

Type of Change

Bug fix

Testing

Script used to test:

from strands import Agent
from strands.models import BedrockModel
from strands_tools import calculator

## change the model-id to any foundation model enabled in your AWS Account
model = BedrockModel(
    model_id="us.anthropic.claude-opus-4-20250514-v1:0", #Or us.writer.palmyra-x4-v1:0
    temperature=0.3,
    streaming=False,
    region_name="us-west-2"
)

agent = Agent(
    model=model,
    tools=[calculator],
    system_prompt="You are an enterprise assistant that helps automate business workflows.",
)

response = agent("tell me what is square root of 64 times 2")

• I ran hatch run prepare

Checklist

• I have read the CONTRIBUTING document
• I have added any necessary tests that prove my fix is effective or my feature works
• I have updated the documentation accordingly
• I have added an appropriate example to the documentation to outline the feature, or no new docs are needed
• My changes generate no new warnings
• Any dependent changes have been merged and published

---

Sources:

• https://github.com/writer/aws-examples/blob/main/bedrock-examples/web-search-agent/agent.py
• https://aws.amazon.com/blogs/aws/writer-palmyra-x5-and-x4-foundation-models-are-now-available-in-amazon-bedrock/
  By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[mehtarac]

Note:

During my testing, I was able to test with multiple models and I had varying results in comparison with the issue reporter in #554. For example, I was able to get successful tool execution with the status field for models:

• anthropic.claude-3-7-sonnet-20250219-v1:0
• anthropic.claude-opus-4-20250514-v1:0

---

More interestingly, after this change I am seeing the model us.writer.palmyra-x4-v1:0 successfully execute tool calls. However, the model us.writer.palmyra-x5-v1:0 is running into an error below:

An error occurred (ValidationException) when calling the Converse operation: The model returned the following errors: {"body":{},"content_type":"application/json","metering":{"inputTokenCount":0,"outputTokenCount":0},"error":{"error_code":400,"error_msg":"Message at index 2 has empty or missing content"}}

I suspect the issue is that Writer Palmyra X4 and X5 have different tool calling implementations in Amazon Bedrock. Palmyra X4 properly supports tool results and can process toolResult blocks with just toolUseId and content fields, while Palmyra X5 appears to have a different tool calling implementation that fails to process tool results entirely, regardless of the field
structure. This suggests that Palmyra X5 either doesn't fully support the Bedrock Converse API's tool calling workflow or has a bug in its tool result processing that causes it to reject valid tool result messages.

[azaylamba]

I am able to use the status field with amazon.nova-pro-v1:0 as well.

[zastrowm]

In a comment you indicated:

During my testing, I was able to test with multiple models and I had varying results in comparison with the issue reporter in #554. For example, I was able to get successful tool execution with the status field for models:

anthropic.claude-3-7-sonnet-20250219-v1:0
anthropic.claude-opus-4-20250514-v1:0

Which makes me wonder if we need to expand this to include all anthropic models.