Increased allowable empty context size to remove need for EmptyDocsError

src/paperqa/docs.py

@@ -26,7 +26,7 @@
     NumpyVectorStore,
     VectorStore,
 )
-from paperqa.prompts import CANNOT_ANSWER_PHRASE
+from paperqa.prompts import CANNOT_ANSWER_PHRASE, EMPTY_CONTEXTS
 from paperqa.readers import read_doc
 from paperqa.settings import MaybeSettings, get_settings
 from paperqa.types import Doc, DocDetails, DocKey, PQASession, Text
@@ -774,9 +774,10 @@ async def aquery(
             pre_str=pre_str,
         )
 
-        if len(context_str.strip()) < 10:  # noqa: PLR2004
+        if len(context_str.strip()) <= EMPTY_CONTEXTS:
             answer_text = (
-                f"{CANNOT_ANSWER_PHRASE} this question due to insufficient information."
+                f"{CANNOT_ANSWER_PHRASE} this question due to"
+                f" {'having no papers' if not self.docs else 'insufficient information.'}."
             )
             answer_reasoning = None
         else:

src/paperqa/prompts.py

@@ -146,5 +146,6 @@
 )
 
 CONTEXT_OUTER_PROMPT = "{context_str}\n\nValid Keys: {valid_keys}"
+EMPTY_CONTEXTS = len(CONTEXT_OUTER_PROMPT.format(context_str="", valid_keys="").strip())
 CONTEXT_INNER_PROMPT_NOT_DETAILED = "{name}: {text}"
 CONTEXT_INNER_PROMPT = f"{CONTEXT_INNER_PROMPT_NOT_DETAILED}\nFrom {{citation}}"

tests/test_agents.py

@@ -475,7 +475,7 @@ async def test_timeout(agent_test_settings: Settings, agent_type: str | type) ->
         settings=agent_test_settings,
         agent_type=agent_type,
     )
-    # ensure that GenerateAnswerTool was called
+    # Ensure that GenerateAnswerTool was called in truncation's failover
     assert response.status == AgentStatus.TRUNCATED, "Agent did not timeout"
     assert CANNOT_ANSWER_PHRASE in response.session.answer