MCPToolAdapter.invoke() was reading error messages from result.get('error',
'unknown error'), but the MCP 1.4.0 protocol returns errors in the content
field as a list of content items with type and text keys. This caused every
error from a real MCP 1.4.0-compliant server to be silently replaced with
the string 'unknown error'.
Changes:
- src/cleveragents/mcp/adapter.py: extract error_text from content[0].text
with safe guards (isinstance check, length check) and fallback to
'unknown error' when content is absent or empty
- features/mocks/mock_mcp_transport.py: return MCP 1.4.0-compliant error
responses using content list format instead of the non-standard error key
- features/tdd_mcp_error_content_key.feature: Behave scenario verifying
correct error extraction from MCP 1.4.0 content arrays (written as TDD
issue-capture, @tdd_expected_fail removed after fix applied)
- features/steps/tdd_mcp_error_content_key_steps.py: step definitions for
the new scenario including _MCP14ErrorTransport mock subclass
All 51 MCP adapter scenarios pass. Typecheck: 0 errors. Lint: clean.
ISSUES CLOSED: #2158
freemo