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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>
This commit is contained in:
olaservo 2026-08-01 21:30:22 -07:00
commit 506e1f70de
3 changed files with 4 additions and 4 deletions
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2
mcp-client-rust/README.md
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@ -2,7 +2,7 @@
See the [Build an MCP client](https://modelcontextprotocol.io/docs/develop/build-client) tutorial for more information.
## Structured output
## Structured content
rmcp does not validate tool output, so this client compiles each declared `outputSchema` at connect time and checks results against it — the spec's client-side SHOULD. It uses the [`jsonschema`](https://docs.rs/jsonschema) crate, which rmcp's own documentation recommends.

2
weather-server-rust/README.md
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@ -2,7 +2,7 @@
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.

4
weather-server-rust/src/main.rs
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@ -68,7 +68,7 @@ struct ForecastPeriod {
detailed_forecast: String,
}
/// One element of `get_alerts`' structured output. Declaring `Vec<Alert>` as
/// One element of `get_alerts`' structured content. Declaring `Vec<Alert>` as
/// the output schema makes `structuredContent` a top-level JSON array rather
/// than an object wrapping one, which revision 2026-07-28 is the first to allow.
#[derive(Debug, Serialize, JsonSchema)]
@ -85,7 +85,7 @@ pub struct Alert {
instructions: String,
}
/// `get_forecast`' structured output: the object case.
/// `get_forecast`' structured content: the object case.
#[derive(Debug, Serialize, JsonSchema)]
pub struct Forecast {
/// Latitude the forecast is for.