fix(anthropic): guard tools event emission with truthiness check

[QuentinBisson]

What

event_emitter.py checks if kwargs.get("tools") is not None: before emitting
tool MessageEvents. anthropic.NOT_GIVEN (the sentinel used for omitted
parameters) is not None, so on tool-free requests the sentinel leaks into the
OTLP log body.

Fix

Change the guard to if kwargs.get("tools"):, matching the system truthiness
check two lines above.

Severity: observability-only — produces noisy/wrong log records, no functional
impact on the instrumented application.

Summary by CodeRabbit

Bug Fixes

• Corrected event emission behavior to prevent unnecessary tool-related events when tool definitions are not provided.

Tests

• Added test coverage for edge cases in tool parameter handling.

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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 84481421-312b-4d06-affe-0bab23338dfa

📥 Commits

Reviewing files that changed from the base of the PR and between d7aaf6c and 68f8d49.

📒 Files selected for processing (2)

• packages/opentelemetry-instrumentation-anthropic/opentelemetry/instrumentation/anthropic/event_emitter.py
• packages/opentelemetry-instrumentation-anthropic/tests/test_semconv_span_attrs.py

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📝 Walkthrough

Walkthrough

In emit_input_events, the condition guarding tool-definition event emission is changed from kwargs.get("tools") is not None to if kwargs.get("tools"):, preventing falsy values like anthropic.NOT_GIVEN from triggering a tools event. A regression test is added to verify the corrected behavior.

Changes

Tools guard fix and regression test

Layer / File(s)	Summary
Tools truthiness guard fix and regression test packages/opentelemetry-instrumentation-anthropic/opentelemetry/instrumentation/anthropic/event_emitter.py, packages/opentelemetry-instrumentation-anthropic/tests/test_semconv_span_attrs.py	Switches the tools condition from an identity check (is not None) to a truthiness check (if kwargs.get("tools"):), and adds test_emit_input_events_not_given_tools_emits_no_tools_event to assert that passing tools=anthropic.NOT_GIVEN results in exactly one emitted event with name gen_ai.user.message.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Possibly related issues

• 🐛 Bug Report: Anthropic event emitter leaks NOT_GIVEN sentinel into log Body, breaking OTLP log export #4230: The one-line fix directly addresses the bug described in this issue, where anthropic.NOT_GIVEN (a falsy sentinel) was leaking into event bodies because the old is not None guard evaluated it as truthy.

Poem

A sentinel snuck through the gate, oh my!
NOT_GIVEN is falsy — let it pass by.
One truthiness check, a bunny's quick hop,
No phantom tool events, the leaking does stop.
🐇✨ The test now confirms it — hip-hop hooray!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: implementing a truthiness check to guard tools event emission, which is the core fix addressing the sentinel value leaking issue.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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