fix: Update README.md

Author: jirispilka

README.md

@@ -178,6 +178,14 @@ Here is an overview list of all the tools provided by the Apify MCP Server.
 
 > The `get-actor-output` tool is automatically included with any Actor-related tool, such as `call-actor`, `add-actor`, or any specific Actor tool like `apify-slash-rag-web-browser`. When you call an Actor - either through the `call-actor` tool or directly via an Actor tool (e.g., `apify-slash-rag-web-browser`) - you receive a preview of the output. The preview depends on the Actor's output format and length; for some Actors and runs, it may include the entire output, while for others, only a limited version is returned to avoid overwhelming the LLM. To retrieve the full output of an Actor run, use the `get-actor-output` tool (supports limit, offset, and field filtering) with the `datasetId` provided by the Actor call.
 
+### Tool annotations
+
+All tools include metadata annotations to help MCP clients and LLMs understand tool behavior:
+
+- **`title`**: Short display name for the tool (e.g., "Search Actors", "Call Actor", "apify/rag-web-browser")
+- **`readOnlyHint`**: `true` for tools that only read data without modifying state (e.g., `get-dataset`, `fetch-actor-details`)
+- **`openWorldHint`**: `true` for tools that access external resources outside the Apify platform (e.g., `call-actor` executes external Actors, `get-html-skeleton` scrapes external websites). Tools that interact only with the Apify platform (like `search-actors` or `fetch-apify-docs`) do not have this hint.
+
 ### Tools configuration
 
 The `tools` configuration parameter is used to specify loaded tools - either categories or specific tools directly, and Apify Actors. For example, `tools=storage,runs` loads two categories; `tools=add-actor` loads just one tool.