* `description`: a `str` with a short description for the tag. It can have Markdown and will be shown in the docs UI.
* `externalDocs`: a `dict` describing external documentation with:
    * `description`: a `str` with a short description for the external docs.
    * `url` (**required**): a `str` with the URL for the external documentation.

}

// ObjectMetricSource indicates how to scale on a metric describing a
// kubernetes object (for example, hits-per-second on an Ingress object).
message ObjectMetricSource {
  // describedObject specifies the descriptions of a object,such as kind,name apiVersion
  optional CrossVersionObjectReference describedObject = 1;

  // target specifies the target value for the given metric
  optional MetricTarget target = 2;

    ```

=== "Python 3.8+"

    ```Python hl_lines="20-21"
    {!> ../../../docs_src/path_operation_configuration/tutorial003.py!}
    ```

## Description from docstring

### OpenAPI

**FastAPI** génère un "schéma" contenant toute votre API dans le standard de définition d'API **OpenAPI**.

#### "Schéma"

Un "schéma" est une définition ou une description de quelque chose. Pas le code qui l'implémente, uniquement une description abstraite.

#### "Schéma" d'API

{
    "responses": {
        "404": {
            "description": "Additional Response",
            "content": {
                "application/json": {
                    "schema": {
                        "$ref": "#/components/schemas/Message"
                    }
                }
            }
        },
        "200": {
            "description": "Successful Response",
            "content": {

{
    "responses": {
        "404": {
            "description": "Additional Response",
            "content": {
                "application/json": {
                    "schema": {
                        "$ref": "#/components/schemas/Message"
                    }
                }
            }
        },
        "200": {
            "description": "Successful Response",
            "content": {

### OpenAPI

**FastAPI** generates a "schema" with all your API using the **OpenAPI** standard for defining APIs.

#### "Schema"

A "schema" is a definition or description of something. Not the code that implements it, but just an abstract description.

#### API "schema"

## 0.16.0

* Upgrade *path operation* `docstring` parsing to support proper Markdown descriptions. New documentation at [Path Operation Configuration](https://fastapi.tiangolo.com/tutorial/path-operation-configuration/#description-from-docstring). PR [#163](https://github.com/tiangolo/fastapi/pull/163).

## Documentation Summary and Description - OpenAPI

To add a summary and description to your *path operations*, and show them in the docs UI, read the docs for [Tutorial - Path Operation Configurations - Summary and Description](../tutorial/path-operation-configuration.md#summary-and-description){.internal-link target=_blank}.

## Documentation Response description - OpenAPI

        if (versionMatcher.matches(PlatformVersion)) {
          val description = StringDescription()
          versionMatcher.describeTo(description)
          description.appendText(" expected to fail with exception that ")
          failureMatcher.describeTo(description)

          fail<Any>(description.toString())
        }
      }
    }