fix(tools): raise ToolUsageError instead of bare raise in _original_tool_calling

[C0d3N1nja97342]

Problem

ToolUsage._original_tool_calling (lib/crewai/src/crewai/tools/tool_usage.py) executed a bare raise outside any except block when _validate_tool_input returned a non-dict and raise_error=True. Because no exception was active on that path (the preceding try/except had completed normally), Python raised RuntimeError: No active exception to re-raise instead of a meaningful error. This produced a confusing error message and caused the caller _tool_calling to log/retry against a RuntimeError rather than a descriptive ToolUsageError.

Reported in #6430.

Solution

Construct a ToolUsageError once and raise it when raise_error=True (or return it when raise_error=False), mirroring the existing raise_error=False return path. The sole caller _tool_calling still catches it via except Exception and falls back to _function_calling / retry exactly as before, so behavior is backward compatible — the only difference is that the exception now carries a meaningful message instead of RuntimeError.

No signature, return-type annotation, or public API change. Minimal and scoped to the bug.

Changes

• lib/crewai/src/crewai/tools/tool_usage.py — in _original_tool_calling, replaced the bare raise in the non-dict branch with raise tool_arguments_error (a constructed ToolUsageError); the raise_error=False path returns the same object.
• lib/crewai/tests/tools/test_tool_usage.py — added ToolUsageError import, a small ToolUsage builder helper, and 3 tests covering:
  • happy path (valid dict → ToolCalling)
  • non-dict + raise_error=True → raises ToolUsageError (regression: was RuntimeError)
  • non-dict + raise_error=False → returns ToolUsageError (compatibility)

Testing

• New unit tests pass: uv run pytest lib/crewai/tests/tools/test_tool_usage.py -k original_tool_calling → 3 passed.
• A minimal runtime demo verified all three paths (happy / raise / return).
• ruff check and ruff format --check are clean on the changed files.
• Note: 5 pre-existing event-bus tests in test_tool_usage.py fail locally on a clean main checkout (confirmed via git stash + re-run) — they are environment/flaky (threading + event bus on Windows) and unrelated to this change.

Notes for Reviewer

• This is an AI-assisted contribution. Per .github/CONTRIBUTING.md, the llm-generated label is required — I've attempted to apply it; if the tooling does not permit external contributors to label PRs, please add it.
• Fixes [BUG] Bare raise in ToolUsage._original_tool_calling causes RuntimeError instead of ToolUsageError #6430.
• Design choice: I kept the defensive if not isinstance(arguments, dict) branch rather than removing it. Since _validate_tool_input currently guarantees dict-or-raise, the branch is effectively defensive/dead, but I chose the minimal fix (correct the raise) over removing the branch to keep the change scoped to the bug. Happy to remove the branch instead if preferred.

[coderabbitai]

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

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Run ID: 694a22a0-a2e4-43a8-a423-10869a0d40b1

📥 Commits

Reviewing files that changed from the base of the PR and between 2b90117 and f4c3aec.

📒 Files selected for processing (2)

• lib/crewai/src/crewai/tools/tool_usage.py
• lib/crewai/tests/tools/test_tool_usage.py

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📝 Walkthrough

Walkthrough

The PR fixes a bare raise statement in ToolUsage._original_tool_calling that caused a RuntimeError instead of a meaningful ToolUsageError when tool arguments were not a dict. It also adds regression tests covering both raise_error=True and raise_error=False paths.

Changes

Bare Raise Fix and Regression Tests

Layer / File(s)	Summary
Explicit error raising lib/crewai/src/crewai/tools/tool_usage.py	Constructs a named ToolUsageError instance for non-dict arguments and raises that same instance when raise_error=True, or returns it when raise_error=False, replacing the previous bare raise.
Regression tests lib/crewai/tests/tools/test_tool_usage.py	Imports ToolUsageError, adds a helper _build_tool_usage_for_original_calling, and adds tests verifying valid dict input yields ToolCalling and non-dict input yields ToolUsageError via raise or return.

Related Issues: #6430

Suggested Labels: bug, tests

Suggested Reviewers: None specifically identified

Poem

A bare raise lurked with no exception near,
Now a ToolUsageError makes the failure clear.
Tests stand watch, both raise and return,
No more RuntimeError for us to discern.
A rabbit hops on, code fixed and bright. 🐇

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly states the core fix in _original_tool_calling and matches the changeset.
Description check	✅ Passed	The description accurately describes the bug, fix, and added tests in the PR.
Linked Issues check	✅ Passed	The change raises ToolUsageError on the non-dict path, preserves the false branch, and adds regression tests as requested in #6430.
Out of Scope Changes check	✅ Passed	The diff stays scoped to tool_usage.py and its tests, with no unrelated changes.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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