fix: honor exit_conditions when LLM emits parallel tool calls

[Aarkin7]

Related Issues

• fixes Agent does not exit when LLM emits parallel tool calls and the exit-condition tool is not the first one #11392

Proposed Changes:

Agent._check_exit_conditions was reading msg.tool_call (singular), which only returns the first ToolCall in the message. So when the LLM emitted a parallel batch like [search, finish] with exit_conditions=["finish"], the finish call was invisible to the exit check and the agent kept looping silently until max_agent_steps was reached.

Switched to iterating msg.tool_calls (plural) so every call in the batch is checked. The existing error-suppression behaviour is preserved, if the exit-condition tool errored, the agent still does not exit. The helper is shared by both run and run_async, so one fix covers both flows.

How did you test it?

• Added 3 regression unit tests in test/components/agents/test_agent.py covering: exit-condition tool not first in the batch, error on the exit tool (must not exit), error only on a sibling non-exit tool (must still exit).
• hatch run test:unit test/components/agents/ → 146 passed, no regressions.
• hatch run test:types and hatch run fmt → clean.

Notes for the reviewer

Behaviour-correcting bug fix, not a breaking change.

Checklist

• I have read the contributors guidelines and the code of conduct.
• I have updated the related issue with new insights and changes.
• I have added unit tests and updated the docstrings.
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test: and added ! in case the PR includes breaking changes.
• I have documented my code.
• I have added a release note file, following the contributors guidelines.
• I have run pre-commit hooks and fixed any issue.

[vercel]

@Aarkin7 is attempting to deploy a commit to the deepset Team on Vercel.

A member of the Team first needs to authorize it.

[github-actions]

Coverage report

Click to see where and how coverage changed

File	Statements	Missing	Coverage	Coverage (new stmts)	Lines missing
haystack/components/agents
agent.py
Project Total

This report was generated by python-coverage-comment-action

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
haystack-docs	Ignored	Preview	May 26, 2026 7:29am

[sjrl]

Thanks for the contribution!