clarify how to reference operationId and workflowId in case of cl…

…ashes

versions/1.0.0.md

@@ -322,9 +322,9 @@ Field Name | Type | Description
 ---|:---:|---
 <a name="stepDescription"></a>description | `string` | A description of the step. [CommonMark syntax](https://spec.commonmark.org/) MAY be used for rich text representation.
 <a name="stepId"></a>stepId | `string` | **REQUIRED**. Unique string to represent the step. The id SHOULD be unique amongst all steps described in the workflow. The stepId value is **case-sensitive**. Tools and libraries MAY use the stepId to uniquely identify a workflow step, therefore, it is RECOMMENDED to follow common programming naming conventions. SHOULD conform to the regular expression `[A-Za-z0-9_\-]+`.
-<a name="stepOperationId"></a>operationId | `string` | The name of an existing, resolvable operation, as defined with a unique `operationId` and existing within one of the `source` descriptions. The referenced operation will be invoked by this workflow step. If more than one (non `workflowsSpec` type) `source` description is defined within a Workflows Description, then the `operationId` specified MUST be prefixed with the source name to avoid ambiguity or potential clashes. This field is mutually exclusive of the `operationRef` and `workflowId` fields respectively.
+<a name="stepOperationId"></a>operationId | `string` | The name of an existing, resolvable operation, as defined with a unique `operationId` and existing within one of the `sourceDescriptions`. The referenced operation will be invoked by this workflow step. If multiple (non `workflowsSpec` type) `sourceDescriptions` are defined, then the `operationId` MUST be specified using a [runtime expression](#runtime-expressions) (e.g., `$sourceDescriptions.<name>.<operationId>`) to avoid ambiguity or potential clashes. This field is mutually exclusive of the `operationRef` and `workflowId` fields respectively.
 <a name="stepOperationRef"></a>operationRef | `string` | A relative or absolute URI reference to an OAS operation. This field is mutually exclusive of the `operationId` and `workflowId` fields respectively. A complete [URI Template](https://www.rfc-editor.org/rfc/rfc6570) SHOULD be used. The operation being referenced MUST be described within one of the `source` descriptions. 
-<a name="stepWorkflowId"></a>workflowId | `string` | The [workflowId](#fixed-fields-2) referencing an existing workflow within the Workflows Description. If more than one `workflowsSpec` type `source` description is defined within a Workflows Description, then the `workflowId` specified MUST be prefixed with the source name to avoid ambiguity or potential clashes. The field is mutually exclusive of the `operationId` and `operationRef` fields respectively.
+<a name="stepWorkflowId"></a>workflowId | `string` | The [workflowId](#fixed-fields-2) referencing an existing workflow within the Workflows Description. If multiple `workflowsSpec` type `sourceDescriptions` are defined, then the `workflowId` MUST be specified using a [runtime expression](#runtime-expressions) (e.g., `$sourceDescriptions.<name>.<workflowId>`) to avoid ambiguity or potential clashes. The field is mutually exclusive of the `operationId` and `operationRef` fields respectively.
 <a name="stepParameters"></a>parameters | [[Parameter Object](#parameter-object) \| [Reference Object](#reference-object)] | A list of parameters to pass to an operation or workflow as referenced by `operationId`, `operationRef`, or `workflowId`. If a Reference Object is provided, it MUST link to parameters defined in [components/parameters](#component-object).
 <a name="dependsOn"></a>dependsOn | [`string`] | A list of steps that MUST be completed before this step can be processed. This helps to ensure workflow steps are executed in the correct order and that dependent steps are not processed in parallel. The values provided MUST be the be the `stepId` which uniquely references a step.
 <a name="stepSuccessCriteria"></a>successCriteria | [[Criterion Object](#criterion-object)] | A list of assertions to determine the success of the step. Each assertion is described using a [Criterion Object](#criterion-object). All assertions `MUST` be satisfied for the step to be deemed successful.
@@ -468,7 +468,7 @@ A single success action which describes an action to take upon success of a work
 Field Name | Type | Description
 ---|:---:|---
 <a name="successActionType"></a> type | `string` | **REQUIRED**. The type of action to take. Possible values are `"end"` or `"goto"`.
-<a name="successWorkflowId"></a> workflowId | `string` | The [workflowId](#fixed-fields-2) referencing an existing workflow within the Workflows Description to transfer to upon success of the step. This field is only relevant when the `type` field value is `"goto"`. If more than one `workflowsSpec` type `source` description is defined within a Workflows Description, then the `workflowId` specified MUST be prefixed with the source name to avoid ambiguity or potential clashes.  This field is mutually exclusive to `stepId`.
+<a name="successWorkflowId"></a> workflowId | `string` | The [workflowId](#fixed-fields-2) referencing an existing workflow within the Workflows Description to transfer to upon success of the step. This field is only relevant when the `type` field value is `"goto"`. If multiple `workflowsSpec` type `sourceDescriptions` are defined, then the `workflowId` MUST be specified using a [runtime expression](#runtime-expressions) (e.g., `$sourceDescriptions.<name>.<workflowId>`) to avoid ambiguity or potential clashes.  This field is mutually exclusive to `stepId`.
 <a name="successStepId"></a> stepId | `string` | The `stepId` to transfer to upon success of the step. This field is only relevant when the `type` field value is `"goto"`. The referenced `stepId` MUST be within the current workflow. This field is mutually exclusive to `workflowId`.
 <a name="successCriteria"></a> criteria | [[Criterion Object](#criterion-object)] | A list of assertions to determine if this action SHALL be executed. Each assertion is described using a [Criterion Object](#criterion-object). All criteria assertions `MUST` be satisfied for the action to be executed.
 
@@ -500,7 +500,7 @@ A single failure action which describes an action to take upon failure of a work
 Field Name | Type | Description
 ---|:---:|---
 <a name="failureActionType"></a> type | `string` | **REQUIRED**. The type of action to take. Possible values are `"end"`, `"retry"`, or `"goto"`.
-<a name="failureWorkflowId"></a> workflowId | `string` | The [workflowId](#fixed-fields-2) referencing an existing workflow within the Workflows Description to transfer to upon failure of the step. This field is only relevant when the `type` field value is `"goto"` or `"retry"`. If more than one `workflowsSpec` type `source` description is defined within a Workflows Description, then the `workflowId` specified MUST be prefixed with the source name to avoid ambiguity or potential clashes.  This field is mutually exclusive to `stepId`. When used with `"retry"`, context transfers back upon completion of the specified workflow.
+<a name="failureWorkflowId"></a> workflowId | `string` | The [workflowId](#fixed-fields-2) referencing an existing workflow within the Workflows Description to transfer to upon failure of the step. This field is only relevant when the `type` field value is `"goto"` or `"retry"`. If multiple `workflowsSpec` type `sourceDescriptions` are defined, then the `workflowId` MUST be specified using a [runtime expression](#runtime-expressions) (e.g., `$sourceDescriptions.<name>.<workflowId>`) to avoid ambiguity or potential clashes.  This field is mutually exclusive to `stepId`. When used with `"retry"`, context transfers back upon completion of the specified workflow.
 <a name="failureStepId"></a> stepId | `string` | The `stepId` to transfer to upon failure of the step. This field is only relevant when the `type` field value is `"goto"` or `"retry"`. The referenced `stepId` MUST be within the current workflow. This field is mutually exclusive to `workflowId`. When used with `"retry"`, context transfers back upon completion of the specified step.
 <a name="failureRetryAfter"></a> retryAfter | `number` | A non-negative decimal indicating the milliseconds delay after the step failure before another attempt SHALL be made. **Note:** if an HTTP [Retry-After](https://www.rfc-editor.org/rfc/rfc9110.html#name-retry-after) response header was returned to a step from a targeted operation, then it SHOULD overrule this particular field value. This field only applies when the `type` field value is `"retry"` or `"function"`.
 <a name="failureRetryLimit"></a> retryLimit | `integer` | A non-negative integer indicating how many attempts to retry the step MAY be attempted before failing the overall step. If not specified then a single retry SHALL be attempted. This field only applies when the `type` field value is `"retry"`. The `retryLimit` MUST be exhausted prior to executing subsequent failure actions.
@@ -702,7 +702,7 @@ A runtime expression allows values to be defined based on information that will
 The runtime expression is defined by the following [ABNF](https://tools.ietf.org/html/rfc5234) syntax:
 
 ```abnf
-      expression = ( "$url" / "$method" / "$statusCode" / "$request." source / "$response." source / "$message." source / "$inputs." name / "$outputs." name / "$steps." name / "$workflows." name)
+      expression = ( "$url" / "$method" / "$statusCode" / "$request." source / "$response." source / "$message." source / "$inputs." name / "$outputs." name / "$steps." name / "$workflows." name / "$sourceDescriptions." name)
       source = ( header-reference / query-reference / path-reference / body-reference )
       header-reference = "header." token
       query-reference = "query." name