Fix hierarchical delegation bug where manager couldn't delegate to all crew agents (#3887)

[devin-ai-integration]

Fix hierarchical delegation bug where manager couldn't delegate to all crew agents (#3887)

Summary

Fixes a bug in hierarchical process where the manager agent's delegation tools were incorrectly limited to only the task's assigned agent instead of all crew agents. This caused delegation errors when the manager tried to delegate to other agents in the crew.

The Fix: Changed one line in crew.py (_update_manager_tools method) to pass self.agents instead of [task.agent] when injecting delegation tools for hierarchical crews with assigned tasks.

Changes:

• lib/crewai/src/crewai/crew.py: Updated line 1125 to pass all crew agents to delegation tools
• lib/crewai/tests/test_crew.py: Added 2 comprehensive tests reproducing the bug scenario and updated 1 existing test to reflect correct behavior
• lib/crewai/tests/cassettes/*.yaml: Updated VCR cassette from test run

Review & Testing Checklist for Human

This is a YELLOW RISK change - small code change but affects core delegation logic.

• CRITICAL: Test with a real hierarchical crew setup matching issue [BUG] #3887 scenario (custom manager_agent with tasks assigned to it, trying to delegate to crew agents). Verify the manager can now successfully delegate to all crew agents, not just the task's assigned agent.
• Verify this doesn't break any existing hierarchical crew workflows in production or examples. The behavior change is: manager can now delegate to ALL crew agents instead of just the task's assigned agent.
• Review the VCR cassette update in test_hierarchical_crew_creation_tasks_with_async_execution.yaml - it's a new HTTP interaction recording from my test run. Ensure it looks legitimate (it's a tracing API call).

Test Plan Recommendation

1. Create a hierarchical crew with:
   • Custom manager_agent (e.g., "Coordinator")
   • Multiple agents in crew.agents list (e.g., ["Planner", "Developer"])
   • Task assigned to the manager agent
2. In the task execution, have the manager try to delegate to one of the crew agents
3. Before fix: Would get error "coworker mentioned not found, it must be one of the following options: - coordinator"
4. After fix: Should successfully delegate to any crew agent

Notes

• All existing delegation and hierarchical tests pass (14 tests)
• Lint checks pass
• The fix is minimal and surgical - only changes the agents list passed to delegation tools
• Session: https://app.devin.ai/sessions/f33249cff8fc44adbf9b1e333b2a5540
• Requested by: João ([email protected])

[devin-ai-integration]

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