docs(changelog): note breaking arg/marker checks; parse required

Review follow-ups: an [Unreleased] entry documents the two behaviour
changes operators must know about (undeclared tool arguments are now
rejected; ambiguous multi-marker directories refuse creates instead of
silently picking the first — previously production). The required-list
parser accepts both a Go-literal []string and a decoded-JSON
[]interface{}, with a test — a bare type assertion would silently
disable the CLI env-default for a registry entry loaded from JSON.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Author: ivkou

CHANGELOG.md

@@ -37,6 +37,18 @@
 - Fix: `deploy-stage` failures are now diagnosable. A failed compare (e.g. "One or more processes has errors") carries a nested `errors` tree naming the exact stage → process → node and the reason (empty scheme, orphan node, a reference into another project, …); the tool previously swallowed it and printed only the bare description. A genuinely unrecognized compare status now also lists each offending object with its id, title and the literal status value instead of an anonymous count.
 - Fix: `deploy-stage` gives a definitive good/bad verdict when the progress WebSocket fails (small merges routinely finish and close it before the monitor subscribes). The outcome is decided by the scheme itself: compare is re-run with retries — an empty diff reports a verified success, a leftover diff reports UNCONFIRMED as an error. Previously every fast merge ended with a scary "completion could not be confirmed over the WebSocket" warning on a successful deploy.
 - Feat: full env-var lifecycle from the IDE — `list-variables`, `modify-variable` and `delete-variable` MCP tools. Both write tools are dry-run-by-default and confirm-gated (`confirm="<short_name>#<obj_id>"`): modify shows a current → new diff (rename additionally scans local `.conv.json` files for `{{env_var[@old-name]}}` references), delete shows a red permanent-deletion warning block that the AI must present to the user verbatim — env vars have NO recycle bin. Secrets are always masked in every output; server semantics verified live: modify is partial (omitted fields — including a secret's value — are preserved), `env_var_type` cannot be changed after creation (the server silently ignores it), delete requires project/stage ids.
+- **Breaking / behaviour**: tool calls now REJECT undeclared arguments with an
+  error naming the unknown keys and the accepted list (previously unknown keys
+  were silently dropped — a call could quietly act on the wrong object).
+  Integrations passing stray keys must remove them.
+- **Breaking / behaviour**: `create-process` / `create-state-diagram` /
+  `create-folder` refuse a working directory that contains MORE than one
+  `<id>_<name>.folder/stage.json` marker instead of silently picking the first
+  one (which could target a production stage). Pass the new explicit
+  `folder_id` argument or run from the specific folder's directory.
+- Feature: create tools accept an explicit `folder_id` and report the resolved
+  target ("created in Corezoid folder #N (explicit folder_id / resolved from
+  marker X)") in the result.
 
 ## [2.8.0]
 

plugins/corezoid/mcp-server/tool_args_validation.go

@@ -36,10 +36,8 @@ func buildToolAllowedArgs() {
 					}
 				}
 			}
-			if req, ok := schema["required"].([]string); ok {
-				for _, k := range req {
-					required[k] = true
-				}
+			for _, k := range schemaRequiredList(schema["required"]) {
+				required[k] = true
 			}
 		}
 		toolAllowedArgs[t.Name] = allowed
@@ -78,6 +76,27 @@ func coerceCLIArgs(tool string, args map[string]interface{}) error {
 	return nil
 }
 
+// schemaRequiredList extracts a schema's "required" list whether it is a
+// Go-literal []string (the registry today) or a decoded-JSON []interface{}
+// (a future registry entry loaded from a file) — a bare []string assertion
+// would silently treat the latter as "nothing required" and disable the CLI
+// env-default for that tool.
+func schemaRequiredList(v interface{}) []string {
+	switch req := v.(type) {
+	case []string:
+		return req
+	case []interface{}:
+		out := make([]string, 0, len(req))
+		for _, item := range req {
+			if s, ok := item.(string); ok {
+				out = append(out, s)
+			}
+		}
+		return out
+	}
+	return nil
+}
+
 // toolRequiresArg reports whether the tool's InputSchema marks the argument
 // as required. Used by the CLI to decide when an env-based default is safe
 // to inject.

plugins/corezoid/mcp-server/tool_args_validation_test.go

@@ -60,3 +60,15 @@ func TestUnknownArgsError_EveryToolHasSchema(t *testing.T) {
 		}
 	}
 }
+
+func TestSchemaRequiredList_BothShapes(t *testing.T) {
+	if got := schemaRequiredList([]string{"a", "b"}); len(got) != 2 {
+		t.Errorf("[]string shape: got %v", got)
+	}
+	if got := schemaRequiredList([]interface{}{"a", "b"}); len(got) != 2 {
+		t.Errorf("[]interface{} shape (decoded JSON): got %v", got)
+	}
+	if got := schemaRequiredList(nil); got != nil {
+		t.Errorf("nil: got %v", got)
+	}
+}