sayan-oai b9e8df47da Use MCP server instructions in deferred namespace descriptions (#21053) ...

## Why

MCP servers can provide `instructions` that explain what their tools are
for. Directly exposed MCP namespaces already use those instructions when
a connector description is not available, but deferred `tool_search`
results did not preserve that fallback. The direct path falls back from
connector metadata to server instructions, while the deferred path only
carried `connector_description` and otherwise fell back to generic
namespace text.

That meant a plain MCP server could provide useful model-facing guidance
and still appear as `Tools in the X namespace.` whenever it was
discovered lazily through `tool_search`.

## What changed

- Store one model-facing `namespace_description` on `ToolInfo`, using
connector descriptions for connector-backed tools and server
instructions for plain MCP servers.
- Thread that namespace description through the `tool_search` source
list, search indexing, and returned namespace metadata.
- Add an end-to-end regression test for deferred non-app MCP search
results exposing server instructions as the namespace description.

## Verification

- `cargo test -p codex-tools
search_tool_description_lists_each_mcp_source_once --lib`
- `cargo test -p codex-core --test all
tool_search_uses_non_app_mcp_server_instructions_as_namespace_description`

b9e8df47da · 2026-05-04 19:36:07 +00:00

History

..

src

Use MCP server instructions in deferred namespace descriptions (#21053)

2026-05-04 19:36:07 +00:00

BUILD.bazel

Extract MCP into codex-mcp crate (#15919)

2026-04-01 19:03:26 -07:00

Cargo.toml

[codex] Prune unused codex-mcp API and duplicate helpers (#19524)

2026-04-25 06:36:07 -07:00