fix wrong descriptions of the and additionalProperties keywords

lib/keywords/additionalProperties.js

@@ -4,8 +4,8 @@ import { getKeywordName, Validation } from "../experimental.js";
 
 
 const id = "https://json-schema.org/keyword/additionalProperties";
-const description = `Validation succeeds if the schema validates \
-against each value not matched by other object applicators in this vocabulary.`;
+const description = `addtionalProperties validates against properties not matched by properties \
+or patternProperties in the same sub-schema as additionalProperties.`;
 
 const compile = async (schema, ast, parentSchema) => {
   const propertiesKeyword = getKeywordName(schema.document.dialectId, "https://json-schema.org/keyword/properties");

lib/keywords/definitions.js

@@ -4,8 +4,11 @@ import Validation from "./validation.js";
 
 
 const id = "https://json-schema.org/keyword/definitions";
-const description = `This keyword is used in meta-schemas to identify the \
-required and optional vocabularies available for use in schemas described by that meta-schema.`;
+const description = `The \`$defs\` keyword provides a standardized way to define \
+reusable subschemas within a single schema document, promoting modularity, reducing \
+code duplication, and improving schema organization. Each subschema within $defs has a \
+unique name, acting as a location for referencing, without directly affecting validation; \
+its value must be a valid JSON Schema.`;
 
 const compile = (schema, ast) => pipe(
   Browser.values(schema),