[doc] Contribute a shape for precondition support for tools.

Signed-off-by: Florian ROUËNÉ <florian.rouene@obeosoft.com>

CHANGELOG.adoc

@@ -5,6 +5,7 @@
 === Shapes
 
 - Add tool sections in the View DSL
+- Add support for Precondition Expressions in Tools
 
 === Architectural decision records
 

doc/iterations/2023.10/shapes/add_precondition_on_tool.adoc

@@ -0,0 +1,41 @@
+= (S) Add precondition on tool
+
+== Problem
+
+Today a specifier can add tools to the palette of a diagram description, but it's not possible to determine when the tool should be available or not.
+
+== Key Result
+
+Offers a specifier the ability to declare precondition on tools.
+Tools are only accessible if their preconditions are interpreted as true.
+
+== Solution
+
+Add in the view DSL, a precondition expression to the tool EClass.
+Before retrieve the list of tools in `GetToolSectionsEventHandler`, interpret this expression to determine if the tool must be added to the palette.
+If there is no precondition set, the tool is always added to the palette.
+The only variables given for the precondition interpretation are:
+
+* _self_: the target object
+* _selectedNode_: the diagram element if it's a node
+* _selectedEdge_: the diagram element if it's an edge
+
+=== Scenario
+
+* The specifier adds a new tool to a palette and sets a precondition expression.
+* When users open the diagram representation, they only have access to the tool if its precondition is evaluated to true.
+
+=== Breadboarding
+
+Example of the `Precondition Expression` for a Tool
+
+image::images/add_precondition_on_tool_01.png[precondition_expression_properties]
+
+=== Cutting backs
+
+== Rabbit holes
+
+* This feature only impacts backend, thus it will be available for both diagram representations (legacy and react_flow).
+
+== No-gos
+