* fix(search): surface DuckDuckGo failures instead of reporting an empty result
DDGS execution failures (rate limits, timeouts, blocked HTML/vqd extraction,
SDK errors, and the missing ddgs dependency) were caught in _search_text and
converted into an empty list, so web_search reported "No results found" for
every failure. The agent then read an outage as a query that matched nothing
and rewrote the query instead of trying an alternative.
_search_text now raises DDGSearchError carrying the exception type and message
for those failures, and web_search_tool answers them with a structured
"DuckDuckGo search failed: ..." error. A genuinely empty result set (the SDK's
exact DDGSException("No results found.") sentinel) still returns the existing
"No results found" response, and tool_result_meta classifies the two cases
differently (transient/config vs no_results).
Tests: tests/test_ddg_search_tools.py (three new failure tests red on main),
tests/test_agent_guidance_check.py, tests/test_tool_result_meta.py; ruff check
and ruff format --check clean.
* fix(search): keep DDGS client construction inside the error boundary
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Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
* fix(search): coerce DDG result limits from environment variables
* fix(search): fall back for invalid DDG result limits
---------
Co-authored-by: kwsYegar <331533331+kwsYegar@users.noreply.github.com>
