fix: enrich MCP tool errors with recovery directive for schema drift (Closes #1393) - #1398
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…1393) When an MCP tool returns not_found or validation errors (tool-definition drift where the server-side schema changed but Hermes' cached definition didn't update), the error was returned with no recovery guidance. Agents retried with slightly different arguments in a loop (19 failed sessions/7d). The enriched error now appends a Recovery directive telling the agent to use tool_describe or tool_search to check the current schema and retry with corrected arguments, or find an alternative tool if it no longer exists. Triggers on error text containing: not_found, 'not found', validation, invalid. Closes #1393 Co-Authored-By: Hermes Evolution <evolution@hermes.ai>
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Summary
When an MCP tool returns
not_foundor validation errors (tool-definition drift — the server-side schema changed but Hermes' cached definition didn't update), the error was returned with no recovery guidance. Agents retried with slightly different arguments in a loop — 19 failed sessions in 7 days.Fix
Enriched the
isErrorresponse path in_make_tool_handler(tools/mcp_tool.py). When the error text containsnot_found,not found,validation, orinvalid, a recovery directive is appended:This tells the agent to re-check the schema (via
tool_describe) or find an alternative (viatool_search) instead of retrying the same failing call.Files
tools/mcp_tool.py— error enrichment inisErrorbranch (17 lines added)tests/tools/test_mcp_error_enrichment.py— 8 tests covering all trigger keywords + negative cases (105 lines)Validation
ruff check✓ruff format --check✓pytest tests/tools/test_mcp_error_enrichment.py— 8 passed ✓Closes #1393