fix: emit cache hints from handler macros - #1120
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alexhancock
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* fix(mcp): emit the cache hints 2026-07-28 requires on tools/list `ListToolsResult::with_all_items` leaves `ttlMs` and `cacheScope` unset, and rmcp only strips `resultType` for legacy peers — nothing fills these in. Protocol 2026-07-28 made both fields required on `tools/list` (SEP-2549 `CacheableResult`), so a strict client rejects the response before it reaches a tool call: the TypeScript SDK 2.0.0 client fails with `Invalid result for tools/list: expected number, received undefined` at `ttlMs`. `server/discover` succeeds first, which makes it read like a client bug until you look at the wire. rmcp 3.1.1 fixes this for servers built from `#[tool_handler]` (modelcontextprotocol/rust-sdk#1120). This server hand-writes `ServerHandler::list_tools`, so the macro fix does not reach it. The tool set is derived from the clap tree once in `EcpMcpServer::new` and never changes while the process lives, so the hint is public and any TTL up to the session length would be honest; 60s matches rmcp's own conformance server and keeps a session that outlives an `ecp` upgrade from calling a subcommand the new binary dropped. Peers older than 2026-07-28 predate both fields and keep the legacy wire shape, matching how the macro gates them. Alongside: `cargo update` (rkyv 0.8.18, rmcp 3.1.1, clap 4.6.6, blake3 1.8.6 and their transitive set), and `taiki-e/install-action` to v2.85.10 — tool-manifest updates only, cargo-nextest 0.9.143 among them. * fix(mcp): keep serve_stdio above the test module clippy::items_after_test_module (-D warnings in CI) rejects any item declared after a `#[cfg(test)] mod`.
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Fixes #1114
Motivation and Context
Strict clients using protocol version 2026-07-28 reject list responses that don't include
ttlMsandcacheScope. As a result, servers using the documented handler macros don't work until the first tool or prompt call. This PR fixes that by adding immediately stale public cache hints for modern clients while continuing to omit them for legacy clients. With this fix macro-generatedtools/listandprompts/listresponses include the cache hints required by clients that negotiate protocol version 2026-07-28. Older clients still receive the same legacy wire format.How Has This Been Tested?
Added integration tests
Breaking Changes
None. The new fields are emitted only where the negotiated protocol requires them.
Types of changes
Checklist