## Why
`tool_search` already had solid end-to-end coverage for discovery and
follow-up execution, but it did not prove that distinct pieces of
indexed search text actually work in integration. In particular, we were
not exercising whether unique tool names, descriptions, namespaces,
underscore-expanded dynamic names, and schema-property terms were
sufficient to surface the expected deferred tools.
This change adds focused integration coverage for those term sources so
regressions in search text construction are caught by a real `TestCodex`
flow instead of only by lower-level unit tests.
## What changed
- added a small helper in `core/tests/suite/search_tool.rs` to assert
that a `tool_search_output` contains an expected namespace child tool
- added an MCP integration test that issues several `tool_search_call`s
and verifies distinct query terms match the expected app tools:
- exact tool name: `calendar_timezone_option_99`
- tool description phrase: `uploaded document`
- top-level schema property: `starts_at`
- added a dynamic-tool integration test that verifies distinct query
terms match the expected deferred dynamic tool:
- exact name: `quasar_ping_beacon`
- underscore-expanded name: `quasar ping beacon`
- description phrase: `saffron metronome`
- namespace: `orbit_ops`
- schema property: `chrono_spec`
## Validation
- `cargo test -p codex-core tool_search_matches_`
## Docs
No documentation update needed.