The SDK's malformed-frame ValueError substrings were hand-copied into the
retry classifier and the error summary; a third SDK message would need
both remembered. The mid-tool retry branch no longer clears
partial_tool_names itself — _start_stream_attempt resets it for every
attempt. buffer_anthropic_tool_input's docstring states the trade: the
knob stays on the turn's kwargs and the changed tools block costs one
prompt-cache miss.
For each issue anchor present in BASE 63279301bc non-test .py and absent on HEAD, the BASE comment/docstring block was re-attached at the HEAD location of the code it explained (matched by the distinctive code line / enclosing def). Sentences already covered by an existing HEAD comment were deduped; the issue number always survives. Insert-only: no code lines changed.
