diff --git a/src/Runner.Worker/Handlers/ScriptHandler.cs b/src/Runner.Worker/Handlers/ScriptHandler.cs
index 397d9a176..022b59420 100644
--- a/src/Runner.Worker/Handlers/ScriptHandler.cs
+++ b/src/Runner.Worker/Handlers/ScriptHandler.cs
@@ -164,8 +164,6 @@ namespace GitHub.Runner.Worker.Handlers
             string workingDirectory = null;
             if (!Inputs.TryGetValue("workingDirectory", out workingDirectory))
             {
-                // TODO: figure out how defaults interact with template later
-                // for now, we won't check job.defaults if we are inside a template.
                 if (string.IsNullOrEmpty(ExecutionContext.ScopeName) && ExecutionContext.Global.JobDefaults.TryGetValue("run", out var runDefaults))
                 {
                     if (runDefaults.TryGetValue("working-directory", out workingDirectory))
@@ -180,8 +178,6 @@ namespace GitHub.Runner.Worker.Handlers
             string shell = null;
             if (!Inputs.TryGetValue("shell", out shell) || string.IsNullOrEmpty(shell))
             {
-                // TODO: figure out how defaults interact with template later
-                // for now, we won't check job.defaults if we are inside a template.
                 if (string.IsNullOrEmpty(ExecutionContext.ScopeName) && ExecutionContext.Global.JobDefaults.TryGetValue("run", out var runDefaults))
                 {
                     if (runDefaults.TryGetValue("shell", out shell))
diff --git a/src/Runner.Worker/action_yaml.json b/src/Runner.Worker/action_yaml.json
index 82b24a695..a36a900bc 100644
--- a/src/Runner.Worker/action_yaml.json
+++ b/src/Runner.Worker/action_yaml.json
@@ -120,7 +120,22 @@
                 "hashFiles(1,255)"
             ],
             "sequence": {
-                "item-type": "any"
+                "item-type": "composite-step"
+            }
+        },
+        "composite-step": {
+            "mapping": {
+                "properties": {
+                    "name": "string-steps-context",
+                    "id": "non-empty-string",
+                    "run": {
+                        "type": "string-steps-context",
+                        "required": true
+                    },
+                    "env": "step-env",
+                    "working-directory": "string-steps-context",
+                    "shell": "string-steps-context"
+                }
             }
         },
         "container-runs-context": {
@@ -157,6 +172,35 @@
             "string": {
                 "require-non-empty": true
             }
+        },
+        "string-steps-context": {
+            "context": [
+                "github",
+                "strategy",
+                "matrix",
+                "steps",
+                "job",
+                "runner",
+                "env",
+                "hashFiles(1,255)"
+            ],
+            "string": {}
+        },
+        "step-env": {
+            "context": [
+                "github",
+                "strategy",
+                "matrix",
+                "steps",
+                "job",
+                "runner",
+                "env",
+                "hashFiles(1,255)"
+            ],
+            "mapping": {
+                "loose-key-type": "non-empty-string",
+                "loose-value-type": "string"
+            }
         }
     }
-}
\ No newline at end of file
+}