Two-part fix for the model-emitted XML drift the v1.13.15-codecontext-synth
investigation surfaced (1 raw <invoke> leak observed out of 190 qwen3.6
turns — qwen3.6-35b-a3b-mxfp4 drifts to the Anthropic format when prompted
as an Architect-style agent because Claude Code documentation in its
pre-training corpus uses that shape).
## Parser extension
xml-parser.ts now recognizes BOTH XML tool-call flavors:
- Qwen/Hermes: <tool_call><function=NAME>...<parameter=K>V</parameter>...</function></tool_call>
- Anthropic: <invoke name="NAME"><parameter name="K">V</parameter></invoke>
Both route through the same synthetic-id xml_call_${idx} ToolCall path.
extractToolCallBlocks() and partialXmlOpenerStart() handle both openers
(<tool_call> and <invoke...) so partial buffers don't get prematurely
flushed during streaming.
The existing Qwen parser was tightened to tolerate whitespace around `=`
(<function = name>, <parameter = key>...) so a stray space doesn't get
absorbed into the function name. Name capture is non-whitespace,
non-`>`.
## Unknown-tool recovery hint
New tool-suggestions.ts exports levenshtein() + suggestToolName() +
formatUnknownToolError(). When tool-phase.ts:executeToolCall receives a
toolCall.name that isn't in TOOLS_BY_NAME, the error returned to the
model now includes a "Did you mean: X?" hint based on Levenshtein
distance ≤3 or substring match against Object.keys(TOOLS_BY_NAME).
Targets the qwen3.6 drift to read_file → suggest view_file. Applies to
all unknown tool names, not just <invoke>-derived ones — at the
dispatch layer we no longer know which format produced the call, and
the extra signal is harmless for Qwen-derived calls.
## Test coverage
xml-parser.test.ts: 46 tests, all green. Covers both parsers
(well-formed, malformed, multi-parameter, nested-content), the
partial-opener detector for both flavors, the unified extraction
helper, and the unknown-tool error formatter.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
indifferentketchup
2e1a81de72