diff --git a/docs/openapi-tess.yaml b/docs/openapi-tess.yaml
index 4a3241a..c348a69 100644
--- a/docs/openapi-tess.yaml
+++ b/docs/openapi-tess.yaml
@@ -124,6 +124,7 @@ paths:
         {
           summary: Submit Mos handoff,
           parameters: [{ $ref: '#/components/parameters/correlation' }],
+          requestBody: { $ref: '#/components/requestBodies/MosHandoff' },
           responses: { '200': { description: Receipt } },
         },
     }
@@ -260,6 +261,28 @@ components:
               },
           },
       }
+    MosHandoff:
+      {
+        required: true,
+        content:
+          {
+            application/json:
+              {
+                schema:
+                  {
+                    type: object,
+                    required: [idempotencyKey, summary],
+                    properties:
+                      {
+                        idempotencyKey: { type: string },
+                        summary: { type: string },
+                        context: { type: string },
+                        missionId: { type: string },
+                      },
+                  },
+              },
+          },
+      }
     Attach:
       {
         content:
@@ -277,6 +300,7 @@ components:
                 schema:
                   {
                     type: object,
+                    required: [content, idempotencyKey],
                     properties: { content: { type: string }, idempotencyKey: { type: string } },
                   },
               },
@@ -288,7 +312,14 @@ components:
         content:
           {
             application/json:
-              { schema: { type: object, properties: { approvalRef: { type: string } } } },
+              {
+                schema:
+                  {
+                    type: object,
+                    required: [approvalRef],
+                    properties: { approvalRef: { type: string } },
+                  },
+              },
           },
       }
     Preference:
@@ -323,7 +354,7 @@ components:
                 schema:
                   {
                     type: object,
-                    required: [content, source, category],
+                    required: [content],
                     properties:
                       {
                         content: { type: string },