fix: prevent Bedrock tool call arguments from being silently dropped

[devin-ai-integration]

Summary

Fixes #5275. When using AWS Bedrock LLMs, tool call arguments were silently discarded, causing tools to receive {} instead of the actual parameters.

Root cause: In _parse_native_tool_call, the dict-branch used func_info.get("arguments", "{}"). Bedrock tool calls have no "function" wrapper, so func_info is {}. The .get("arguments", "{}") returns the default "{}" — a truthy string — which short-circuits the or, and tool_call.get("input", {"city": "Paris"}) is never evaluated.

Fix: Remove the truthy default so the or-chain falls through correctly:

# Before (broken for Bedrock)
func_args = func_info.get("arguments", "{}") or tool_call.get("input", {})

# After
func_args = func_info.get("arguments") or tool_call.get("input") or {}

This aligns with extract_tool_call_info in agent_utils.py (line 1224), which already uses the correct pattern.

Review & Testing Checklist for Human

• Verify that OpenAI-format dict tool calls (with "function": {"arguments": ...}) still work — the arguments value is a non-empty JSON string (truthy), so the or should not fall through
• Consider edge case: if arguments is ever an empty string "", it now falls through to input instead of returning "{}". This should be benign (empty string is invalid JSON anyway) but worth confirming no provider sends it
• Recommended test plan: Run a Bedrock-backed agent with a tool that has required parameters (e.g. the TravelTool from the issue) and confirm the tool receives the correct arguments instead of {}

Notes

• The parallel implementation in agent_utils.py:extract_tool_call_info already had the correct pattern and was not affected
• 7 new unit tests added covering Bedrock dict, OpenAI dict, empty args, and nested args for both _parse_native_tool_call and extract_tool_call_info

Link to Devin session: https://app.devin.ai/sessions/f9045bdaa79642948bb2f734e0de5d79

---

Note

Low Risk
Low risk, localized change to native tool-call argument extraction plus new unit coverage; main risk is subtle behavior change when function.arguments is missing/empty causing fallback to input/{}.

Overview
Fixes native tool-call parsing so Bedrock-style dict tool calls no longer drop their input arguments (removes the truthy default "{}" and falls through to tool_call["input"] or {}).

Adds regression/unit tests covering Bedrock vs OpenAI dict formats, empty-args behavior, and nested Bedrock inputs for both CrewAgentExecutor._parse_native_tool_call and agent_utils.extract_tool_call_info.

^{Reviewed by Cursor Bugbot for commit c0c1920. Bugbot is set up for automated code reviews on this repo. Configure here.}

[devin-ai-integration]

Prompt hidden (unlisted session)

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring