Name of sample affected

python/agents/academic-research/academic_research/agent.py (agent.py for short)
python/agents/academic-research/academic_research/sub_agents/academic_websearch/prompt.py (academic_websearch/prompt.py for short)
python/agents/academic-research/academic_research/sub_agents/academic_newresearch/prompt.py (academic_newresearch/prompt.py for short)

Description of issue

Context variable not found: 'seminal _paper' (See the screenshot at the bottom)

Despite output_key="seminal_paper" being specified in agent.py, the key session.state["seminal_paper"] is not created. This occurs because the academic_coordinator agent initiates a function call rather than producing a final textual response during the first step.

As a result, when the prompt in academic_websearch/prompt.py (as well as academic_newresearch/prompt.py) is rendered, the ADK throws an error because the seminal_paper context variable is missing.

Per the ADK documentation,

An Agent can be configured with an output_key="your_key". ADK will then automatically save the agent's final textual response for a turn into session.state["your_key"].

This means output_key does not capture intermediary steps or function calls.

Environment

• OS & Architecture: macOS 15.6.1
• Python version: 3.12.11
• google-adk: 1.18.0

Reproduction steps or code

cd python/agents/academic-research
adk web

The prompt is
The paper in question is Attention Is All You Need as well as the attached paper.

Error log