fix(agents): stop priming tool calls in schema-only structured agents

- with_structured_output binds a single tool (the schema), so a primed model emitted
  an unknown web_search call and the attempt was discarded for a free-text retry,
  costing an extra round trip and the typed output
- drop the tool-range wording from the no-tool sentiment analyst and state the
  constraint once via a shared NO_EXTERNAL_TOOLS #1130

tests/test_structured_agent_prompts.py

@@ -0,0 +1,147 @@
+"""Agents on the schema-only structured-output path must not invite tool calls (#1130).
+
+`with_structured_output` binds exactly one tool (the schema). A prompt that
+primes tool use makes models emit an unknown `web_search` call, which discards
+the structured attempt and forces a free-text retry — an extra LLM round trip
+and the loss of typed output.
+
+These assert the constraint reaches the *rendered* prompt each agent actually
+sends, not merely that the constant is referenced in the module.
+"""
+from __future__ import annotations
+
+import inspect
+from unittest.mock import MagicMock
+
+import pytest
+
+import tradingagents.agents.analysts.sentiment_analyst as sentiment
+from tradingagents.agents.managers.portfolio_manager import create_portfolio_manager
+from tradingagents.agents.managers.research_manager import create_research_manager
+from tradingagents.agents.trader.trader import create_trader
+from tradingagents.agents.utils.structured import NO_EXTERNAL_TOOLS
+
+
+def _capturing_llm(captured: dict, result):
+    """LLM whose structured binding records the prompt it was handed."""
+    structured = MagicMock()
+    structured.invoke.side_effect = lambda prompt: (
+        captured.__setitem__("prompt", prompt) or result
+    )
+    llm = MagicMock()
+    llm.with_structured_output.return_value = structured
+    return llm
+
+
+def _prompt_text(prompt) -> str:
+    """Flatten a captured prompt (str, message list, or objects) to text."""
+    if isinstance(prompt, str):
+        return prompt
+    parts = []
+    for m in prompt:
+        parts.append(m.get("content", "") if isinstance(m, dict) else getattr(m, "content", ""))
+    return "\n".join(str(p) for p in parts)
+
+
+@pytest.mark.unit
+def test_trader_prompt_states_constraint():
+    from tradingagents.agents.schemas import TraderAction, TraderProposal
+
+    captured = {}
+    llm = _capturing_llm(captured, TraderProposal(action=TraderAction.BUY, reasoning="x"))
+    create_trader(llm)({
+        "company_of_interest": "NVDA",
+        "investment_plan": "**Recommendation**: Buy",
+    })
+    assert NO_EXTERNAL_TOOLS in _prompt_text(captured["prompt"])
+
+
+@pytest.mark.unit
+def test_research_manager_prompt_states_constraint():
+    from tradingagents.agents.schemas import PortfolioRating, ResearchPlan
+
+    captured = {}
+    llm = _capturing_llm(
+        captured,
+        ResearchPlan(
+            recommendation=PortfolioRating.BUY, rationale="x", strategic_actions="y"
+        ),
+    )
+    create_research_manager(llm)({
+        "company_of_interest": "NVDA",
+        "investment_debate_state": {
+            "history": "h", "bull_history": "b", "bear_history": "r",
+            "current_response": "", "judge_decision": "", "count": 1,
+        },
+    })
+    assert NO_EXTERNAL_TOOLS in _prompt_text(captured["prompt"])
+
+
+@pytest.mark.unit
+def test_portfolio_manager_prompt_states_constraint():
+    from tradingagents.agents.schemas import PortfolioDecision, PortfolioRating
+
+    captured = {}
+    llm = _capturing_llm(
+        captured,
+        PortfolioDecision(
+            rating=PortfolioRating.HOLD,
+            executive_summary="x",
+            investment_thesis="y",
+        ),
+    )
+    risk = {
+        "history": "h", "aggressive_history": "a", "conservative_history": "c",
+        "neutral_history": "n", "current_aggressive_response": "",
+        "current_conservative_response": "", "current_neutral_response": "",
+        "latest_speaker": "Neutral", "count": 1,
+    }
+    create_portfolio_manager(llm)({
+        "company_of_interest": "NVDA",
+        "risk_debate_state": risk,
+        "investment_plan": "plan",
+        "trader_investment_plan": "trader plan",
+    })
+    assert NO_EXTERNAL_TOOLS in _prompt_text(captured["prompt"])
+
+
+@pytest.mark.unit
+def test_sentiment_prompt_states_constraint(monkeypatch):
+    from tradingagents.agents.schemas import SentimentBand, SentimentReport
+
+    # Pre-fetched sources are stubbed so the prompt builds without network I/O.
+    monkeypatch.setattr(sentiment, "fetch_stocktwits_messages", lambda *a, **k: "st")
+    monkeypatch.setattr(sentiment, "fetch_reddit_posts", lambda *a, **k: "rd")
+    monkeypatch.setattr(sentiment.get_news, "func", lambda *a, **k: "news", raising=False)
+
+    captured = {}
+    llm = _capturing_llm(captured, SentimentReport(
+        overall_band=SentimentBand.BULLISH, overall_score=7.5,
+        confidence="high", narrative="n",
+    ))
+    sentiment.create_sentiment_analyst(llm)({
+        "company_of_interest": "NVDA", "trade_date": "2026-01-15",
+        "asset_type": "stock", "messages": [],
+    })
+    text = _prompt_text(captured["prompt"])
+    assert NO_EXTERNAL_TOOLS in text
+    # This agent binds no tools, so tool-range wording must not reappear.
+    assert "tool-call date ranges" not in text
+
+
+@pytest.mark.unit
+def test_tool_using_analysts_keep_their_date_guidance():
+    # The analysts that really do call tools keep the wording that anchors their
+    # tool date ranges (#836) — this fix is scoped to no-tool agents.
+    import tradingagents.agents.analysts.market_analyst as market
+    import tradingagents.agents.analysts.news_analyst as news
+    for module in (market, news):
+        assert "tool-call date ranges" in inspect.getsource(module)
+
+
+@pytest.mark.unit
+def test_constraint_text_is_unambiguous():
+    assert "do not call external tools" in NO_EXTERNAL_TOOLS.lower()
+    # No template braces: it is embedded in ChatPromptTemplate strings, where
+    # braces would be parsed as input variables.
+    assert "{" not in NO_EXTERNAL_TOOLS and "}" not in NO_EXTERNAL_TOOLS