Two interaction seams between the #92693 salvage (merged as #95050) and
this branch: the source-label indexing test now compares in token space
(the stemmer shortens 'catalogsource' to 'catalogsourc'), and the
unregistered-core-name describe test forces the unregistered condition
via monkeypatch instead of depending on which sibling test file imported
model_tools first.
Four fixes to the tool-search deferral layer, split from PR #92693 (the
availability-cache staleness fix ships separately):
1. The parallel batch planner now peels the tool_call bridge wrapper and
decides admission on the underlying tool — supports_parallel_tool_calls
works again when deferral is active. Unparseable wrappers stay
sequential barriers; bridged calls get exactly the admission the same
call gets direct. tool_search/tool_describe lookups batch concurrently.
2. _short_desc no longer truncates listing lines at 'e.g.', hostnames, or
version strings — a sentence terminator must be followed by whitespace.
3. BM25 indexes the source label (e.g. 'linear' for mcp-linear), so
service-name queries reach tools whose own name omits the service; the
dead 'mcp' prefix token is stripped.
4. Substring-fallback docstring corrected (token misses, not zero-IDF).
Salvaged from #92693 by @alt-glitch with authorship preserved.