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Say "structured content", not "structured output"

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The spec never uses the phrase "structured output". It defines two separate
things under Tool Result: "Structured Content" (the `structuredContent` field)
and "Output Schema" (the `outputSchema` field). Collapsing them into
"structured output" conflates the two.

It is also actively confusing here. In LLM tooling "structured output" means
constrained decoding — making the *model* emit conforming JSON. These clients
call a model API, so a reader could reasonably take the phrase to mean the
tool constrains the model's response, which is the opposite of what is going
on: the tool describes the shape of its own result.

Headings and prose now say "structured content". References to real
identifiers are left alone: the Python SDK's own docs page is called
Structured Output and lives at docs/servers/structured-output.md, and its
decorator parameter is `structured_output`.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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olaservo 2026-08-01 21:30:22 -07:00
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mcp-client-ruby/README.md
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See the [Build an MCP client](https://modelcontextprotocol.io/docs/develop/build-client) tutorial for more information.
## Structured output
## Structured content
The spec says clients SHOULD validate structured results against the schema the tool declares, and this SDK's client does not do it for you — `MCP::Client::Tool#output_schema` hands back the raw schema from the wire and nothing checks results against it. So the client compiles each declared schema once at connect time with `MCP::Tool::OutputSchema.new` and validates every non-error result.

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weather-server-ruby/README.md
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See the [Build an MCP server](https://modelcontextprotocol.io/docs/develop/build-server) tutorial for more information.
## Structured output
## Structured content
Both tools declare an `output_schema` and return `structured_content`. `get_forecast` returns an object; `get_alerts` returns a top-level JSON array, which protocol revision `2026-07-28` is the first to allow — see [Structured Content](https://modelcontextprotocol.io/specification/draft/server/tools#structured-content) in the spec.
@ -14,7 +14,7 @@ The tools also return a human-readable `content` block. When you pass your own `
## Known limitation: strict `2026-07-28` clients reject this server
The `mcp` gem never emits the `resultType` field on results. The 2026-07-28 schema makes it mandatory — "Servers implementing this protocol version MUST include this field" — so a client that enforces the revision rejects every response, including `tools/list`, before it ever reaches the structured output.
The `mcp` gem never emits the `resultType` field on results. The 2026-07-28 schema makes it mandatory — "Servers implementing this protocol version MUST include this field" — so a client that enforces the revision rejects every response, including `tools/list`, before it ever reaches the structured content.
There is no way to set it from user code: `MCP::Server` accepts `ttl_ms:` and `cache_scope:` for the SEP-2549 cache hints, but nothing for `resultType`. The gem's own client does not check the field, so the gap is invisible when a Ruby client talks to a Ruby server, and only appears cross-SDK.