fix(server): normalize bare-boolean subschemas in generated tool schemas

`schemars` emits `true.into()` for `serde_json::Value::json_schema()`, so
`Value` / `Vec<Value>` / `BTreeMap<_, Value>` / `#[serde(deny_unknown_fields)]`
fields produce bare boolean subschemas (`"<name>": true`, `"items": true`,
`additionalProperties: true`/`false`). JSON Schema 2020-12 §4.3.2 explicitly
permits these as `{}` / `{"not": {}}` shortcuts, but Claude Code's
`LocalMcpServerManager` schema walker throws

  TypeError: Cannot use 'in' operator to search for 'properties' in true

while building the per-server proxy after `tools/list` parses successfully,
silently dropping the entire server's tool list for the session
(anthropics/claude-code#50194 — Grafana MCP, current as of CC 2.1.111;
also #25081, #10606, #28620). The TypeScript SDK's Zod validator accepts
bare booleans correctly; the failure is a Claude Code walker defect.

Apply `schemars::transform::ReplaceBoolSchemas::default()` via
`transform_subschemas` (not `SchemaSettings::with_transform`) so

  - bool subschemas in `properties.*`, `items`, `additionalProperties`,
    `prefixItems[*]`, `oneOf`/`anyOf`/`allOf[*]`, `not`/`if`/`then`/`else`,
    `contains`, `propertyNames`, `additionalItems`, `$defs.*`,
    `definitions.*`, `patternProperties.*` are normalized to object form
  - degenerate `Json<serde_json::Value>` roots stay non-`"type":"object"`
    and the existing `schema_for_output` root-type rejection still fires

Patched both `handler::server::common::schema_for_type` (the funnel for
tool/prompt schemas, `Tool::with_input_schema`, `with_output_schema`,
`schema_for_output`, `cached_arguments_from_schema`, and the `#[tool]`
macro default code-gen) and `model::elicitation_schema::ElicitationSchema::from_type`
(the parallel funnel for elicitation prompts). 10 new unit tests pin the
contract: every documented schemars field shape, idempotency, the
canonical #50194 reproducer (`BTreeMap<_, Value>`), and the degenerate
root rejection.

Author: jrmelsha

conformance/Cargo.toml

@@ -22,7 +22,6 @@ rmcp = { path = "../crates/rmcp", features = [
     "transport-streamable-http-client-reqwest",
 ] }
 tokio = { version = "1", features = ["full"] }
-tokio-util = { version = "0.7" }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 tracing = "0.1"

crates/rmcp-macros/Cargo.toml

@@ -18,7 +18,6 @@ proc-macro = true
 syn = {version = "2", features = ["full"]}
 quote = "1"
 proc-macro2 = "1"
-serde_json = "1.0"
 darling = { version = "0.23" }
 
 [features]

crates/rmcp/CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- *(server)* Normalise bare boolean subschemas (`true` / `false`) in generated `inputSchema`, `outputSchema`, and `ElicitationSchema` to their object-form equivalents (`{}` / `{"not": {}}`) before serialisation. Triggered by `serde_json::Value` field expansions, `Vec<serde_json::Value>`, `BTreeMap<String, serde_json::Value>`, and `#[serde(deny_unknown_fields)]`. Claude Code's `LocalMcpServerManager` schema walker throws `TypeError: Cannot use 'in' operator to search for 'properties' in <bool>` on bare booleans, silently dropping the entire server's tool list ([anthropics/claude-code#50194](https://github.com/anthropics/claude-code/issues/50194), [#25081](https://github.com/anthropics/claude-code/issues/25081)). The fix is unconditional — boolean subschemas are spec-legal per JSON Schema 2020-12 §4.3.2, but real-world MCP clients can't always handle them, so emit object form universally.
+
 ## [1.5.0](https://github.com/modelcontextprotocol/rust-sdk/compare/rmcp-v1.4.0...rmcp-v1.5.0) - 2026-04-16
 
 ### Added

crates/rmcp/Cargo.toml

@@ -89,7 +89,6 @@ which = { version = "8", optional = true }
 # tokio-tungstenite ={ version = "0.26", optional = true }
 
 # for http-server transport
-rand = { version = "0.10", optional = true }
 tokio-stream = { version = "0.1", optional = true }
 uuid = { version = "1", features = ["v4"], optional = true }
 http-body = { version = "1", optional = true }
@@ -136,7 +135,6 @@ reqwest-native-tls = ["__reqwest", "reqwest?/native-tls"]
 
 server-side-http = [
   "uuid",
-  "dep:rand",
   "dep:tokio-stream",
   "dep:http",
   "dep:http-body",