fix(anthropic): replace guard with truthiness check to prevent NOT_G…

[nidhithippana]

Fixes #4230

When tools is omitted from a messages.create() call, the Anthropic SDK
defaults it to NOT_GIVEN. The previous is not None guard let this sentinel
through into the log body, causing OTLP export to fail with:

Exception: Invalid type <class 'anthropic.NotGiven'> of value NOT_GIVEN

Changed the guard to a truthiness check (consistent with the existing system
branch above it), which correctly drops both NOT_GIVEN and empty lists.

Added a regression test to verify no sentinel leaks into emitted log bodies.

• [yes] I have added tests that cover my changes.
• [N/A] If adding a new instrumentation or changing an existing one, I've added screenshots from some observability platform showing the change.
• [yes] PR name follows conventional commits format: feat(instrumentation): ... or fix(instrumentation): ....
• [N/A] (If applicable) I have updated the documentation accordingly.

Summary by CodeRabbit

Release Notes

• Bug Fixes

  • Fixed instrumentation event emission behavior for Anthropic message creation when tools are not provided or empty.

• Tests

  • Added regression test to ensure instrumentation logging is correct when tools are omitted.

[CLAassistant]

All committers have signed the CLA.

[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: 959b3f4c-0f14-41c7-920f-e0b4fbca9981

📥 Commits

Reviewing files that changed from the base of the PR and between 4643b88 and 0202d11.

⛔ Files ignored due to path filters (1)

• packages/opentelemetry-instrumentation-anthropic/uv.lock is excluded by !**/*.lock

📒 Files selected for processing (3)

• packages/opentelemetry-instrumentation-anthropic/opentelemetry/instrumentation/anthropic/event_emitter.py
• packages/opentelemetry-instrumentation-anthropic/tests/cassettes/test_messages/test_anthropic_message_create_without_tools_no_sentinel_leak.yaml
• packages/opentelemetry-instrumentation-anthropic/tests/test_messages.py

---

📝 Walkthrough

Walkthrough

Fixes a bug where omitting tools in an Anthropic messages.create() call caused the Anthropic SDK sentinel NOT_GIVEN to leak into the OTel log body. The guard in emit_input_events is changed from is not None to a truthiness check, matching the existing system branch. A VCR-backed regression test and cassette are added to verify no sentinel leaks.

Changes

NOT_GIVEN Sentinel Leak Fix

Layer / File(s)	Summary
Truthiness guard for tools emission packages/opentelemetry-instrumentation-anthropic/opentelemetry/instrumentation/anthropic/event_emitter.py	emit_input_events now uses if kwargs.get("tools") instead of if kwargs.get("tools") is not None, so NOT_GIVEN and empty collections no longer produce a MessageEvent.
Regression test and VCR cassette packages/opentelemetry-instrumentation-anthropic/tests/test_messages.py, packages/opentelemetry-instrumentation-anthropic/tests/cassettes/test_messages/test_anthropic_message_create_without_tools_no_sentinel_leak.yaml	Adds a VCR-backed test asserting that a messages.create call without tools emits exactly two logs and none contain the string NOT_GIVEN.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~5 minutes

Poem

🐇 A sentinel snuck in, NOT_GIVEN by name,
Into the logs it crept, causing export pain.
One truthiness check, a single line swapped,
The sneaky is not None was finally stopped.
Now tools left unset make nary a peep,
And OTLP exports continue their sleep! 🌙

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 25.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 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: replacing an is not None guard with a truthiness check for the tools parameter to fix the NOT_GIVEN sentinel leak issue.
Linked Issues check	✅ Passed	All requirements from issue #4230 are met: the is not None guard is replaced with truthiness check, the fix aligns with existing system parameter handling, and a regression test is added.
Out of Scope Changes check	✅ Passed	All changes are directly related to fixing the NOT_GIVEN sentinel leak issue documented in #4230; no out-of-scope modifications were introduced.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}