feat: Add tool annotations

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.

src/mcp/server.ts

@@ -297,8 +297,8 @@ export class ActorsMcpServer {
             }
         } else {
             // No skyfire mode - store tools as-is
-            for (const wrap of tools) {
-                this.tools.set(wrap.name, wrap);
+            for (const tool of tools) {
+                this.tools.set(tool.name, tool);
             }
         }
         if (shouldNotifyToolsChangedHandler) this.notifyToolsChangedHandler();

src/tools/actor.ts

@@ -198,6 +198,10 @@ Actor description: ${actorDefinitionPruned.description}`;
             inputSchema: inputSchema as ToolInputSchema,
             ajvValidate,
             memoryMbytes,
+            annotations: {
+                title: actorDefinitionPruned.actorFullName,
+                openWorldHint: true,
+            },
         });
     }
     return tools;
@@ -361,6 +365,10 @@ EXAMPLES:
         // Additional props true to allow skyfire-pay-id
         additionalProperties: true,
     }),
+    annotations: {
+        title: 'Call Actor',
+        openWorldHint: true,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken, progressTracker, extra, apifyMcpServer } = toolArgs;
         const { actor: actorName, step, input, callOptions } = callActorArgs.parse(args);

src/tools/build.ts

@@ -116,6 +116,11 @@ export const actorDefinitionTool: ToolEntry = {
         + `Limit the length of the README if needed.`,
     inputSchema: zodToJsonSchema(getActorDefinitionArgsSchema) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(getActorDefinitionArgsSchema)),
+    annotations: {
+        title: 'Get Actor definition',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
 

src/tools/dataset.ts

@@ -57,6 +57,11 @@ USAGE EXAMPLES:
 - user_input: What fields does username~my-dataset have?`,
     inputSchema: zodToJsonSchema(getDatasetArgs) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(getDatasetArgs)),
+    annotations: {
+        title: 'Get dataset',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = getDatasetArgs.parse(args);
@@ -89,6 +94,11 @@ USAGE EXAMPLES:
 - user_input: Get only metadata.url and title from dataset username~my-dataset (flatten metadata)`,
     inputSchema: zodToJsonSchema(getDatasetItemsArgs) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(getDatasetItemsArgs)),
+    annotations: {
+        title: 'Get dataset items',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = getDatasetItemsArgs.parse(args);
@@ -148,6 +158,11 @@ USAGE EXAMPLES:
 - user_input: Show schema of username~my-dataset (clean items only)`,
     inputSchema: zodToJsonSchema(getDatasetSchemaArgs) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(getDatasetSchemaArgs)),
+    annotations: {
+        title: 'Get dataset schema',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = getDatasetSchemaArgs.parse(args);

src/tools/dataset_collection.ts

@@ -42,6 +42,11 @@ USAGE EXAMPLES:
 - user_input: List unnamed datasets`,
     inputSchema: zodToJsonSchema(getUserDatasetsListArgs) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(getUserDatasetsListArgs)),
+    annotations: {
+        title: 'Get user datasets list',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = getUserDatasetsListArgs.parse(args);

src/tools/fetch-actor-details.ts

@@ -29,6 +29,11 @@ USAGE EXAMPLES:
 - user_input: What is the pricing for apify/instagram-scraper?`,
     inputSchema: zodToJsonSchema(fetchActorDetailsToolArgsSchema) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(fetchActorDetailsToolArgsSchema)),
+    annotations: {
+        title: 'Fetch Actor details',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = fetchActorDetailsToolArgsSchema.parse(args);

src/tools/fetch-apify-docs.ts

@@ -29,6 +29,11 @@ USAGE EXAMPLES:
 - user_input: Fetch https://docs.apify.com/academy`,
     inputSchema: zodToJsonSchema(fetchApifyDocsToolArgsSchema) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(fetchApifyDocsToolArgsSchema)),
+    annotations: {
+        title: 'Fetch Apify docs',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args } = toolArgs;
 

src/tools/get-actor-output.ts

@@ -88,6 +88,11 @@ Note: This tool is automatically included if the Apify MCP Server is configured
      * Allow additional properties for Skyfire mode to pass `skyfire-pay-id`.
      */
     ajvValidate: ajv.compile({ ...zodToJsonSchema(getActorOutputArgs), additionalProperties: true }),
+    annotations: {
+        title: 'Get Actor output',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken, apifyMcpServer } = toolArgs;
 

src/tools/get-html-skeleton.ts

@@ -52,6 +52,11 @@ USAGE EXAMPLES:
 - user_input: Get next chunk of HTML skeleton for https://example.com (chunk=2)`,
     inputSchema: zodToJsonSchema(getHtmlSkeletonArgs) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(getHtmlSkeletonArgs)),
+    annotations: {
+        title: 'Get HTML skeleton',
+        readOnlyHint: true,
+        openWorldHint: true,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = getHtmlSkeletonArgs.parse(args);

src/tools/helpers.ts

@@ -27,6 +27,10 @@ USAGE EXAMPLES:
 - user_input: Add apify/instagram-scraper as a tool`,
     inputSchema: zodToJsonSchema(addToolArgsSchema) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(addToolArgsSchema)),
+    annotations: {
+        title: 'Add tool',
+        openWorldHint: true,
+    },
     // TODO: I don't like that we are passing apifyMcpServer and mcpServer to the tool
     call: async (toolArgs: InternalToolArgs) => {
         const { apifyMcpServer, apifyToken, args, extra: { sendNotification } } = toolArgs;

src/tools/key_value_store.ts

@@ -29,6 +29,11 @@ USAGE EXAMPLES:
 - user_input: Get details for store adb123`,
     inputSchema: zodToJsonSchema(getKeyValueStoreArgs) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(getKeyValueStoreArgs)),
+    annotations: {
+        title: 'Get key-value store',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = getKeyValueStoreArgs.parse(args);
@@ -69,6 +74,11 @@ USAGE EXAMPLES:
 - user_input: Continue listing keys in store a123 from key data.json`,
     inputSchema: zodToJsonSchema(getKeyValueStoreKeysArgs) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(getKeyValueStoreKeysArgs)),
+    annotations: {
+        title: 'Get key-value store keys',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = getKeyValueStoreKeysArgs.parse(args);
@@ -107,6 +117,11 @@ USAGE EXAMPLES:
 - user_input: Get record data.json from store username~my-store`,
     inputSchema: zodToJsonSchema(getKeyValueStoreRecordArgs) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(getKeyValueStoreRecordArgs)),
+    annotations: {
+        title: 'Get key-value store record',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = getKeyValueStoreRecordArgs.parse(args);

src/tools/key_value_store_collection.ts

@@ -42,6 +42,11 @@ USAGE EXAMPLES:
 - user_input: List unnamed key-value stores`,
     inputSchema: zodToJsonSchema(getUserKeyValueStoresListArgs) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(getUserKeyValueStoresListArgs)),
+    annotations: {
+        title: 'Get user key-value stores list',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = getUserKeyValueStoresListArgs.parse(args);

src/tools/run.ts

@@ -36,6 +36,11 @@ USAGE EXAMPLES:
 - user_input: What is the datasetId for run y2h7sK3Wc?`,
     inputSchema: zodToJsonSchema(getActorRunArgs) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(getActorRunArgs)),
+    annotations: {
+        title: 'Get Actor run',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = getActorRunArgs.parse(args);
@@ -74,6 +79,11 @@ USAGE EXAMPLES:
 - user_input: Get logs for run y2h7sK3Wc`,
     inputSchema: zodToJsonSchema(GetRunLogArgs) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(GetRunLogArgs)),
+    annotations: {
+        title: 'Get Actor run log',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = GetRunLogArgs.parse(args);
@@ -103,6 +113,10 @@ USAGE EXAMPLES:
 - user_input: Gracefully abort run y2h7sK3Wc`,
     inputSchema: zodToJsonSchema(abortRunArgs) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(abortRunArgs)),
+    annotations: {
+        title: 'Abort Actor run',
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = abortRunArgs.parse(args);

src/tools/run_collection.ts

@@ -40,6 +40,11 @@ USAGE EXAMPLES:
 - user_input: Show only SUCCEEDED runs`,
     inputSchema: zodToJsonSchema(getUserRunsListArgs) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(getUserRunsListArgs)),
+    annotations: {
+        title: 'Get user runs list',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken } = toolArgs;
         const parsed = getUserRunsListArgs.parse(args);

src/tools/search-apify-docs.ts

@@ -34,7 +34,7 @@ export const searchApifyDocsTool: ToolEntry = {
     Apify documentation has information about Apify console, Actors (development
     (actor.json, input schema, dataset schema, dockerfile), deployment, builds, runs),
     schedules, storages (datasets, key-value store), Proxy, Integrations,
-    Apify Academy (crawling and webscraping with Crawlee),
+    Apify Academy (crawling and webscraping with Crawlee).
 
     The results will include the URL of the documentation page, a fragment identifier (if available),
     and a limited piece of content that matches the search query.
@@ -50,6 +50,11 @@ export const searchApifyDocsTool: ToolEntry = {
     - query: How scrape with Crawlee?`,
     inputSchema: zodToJsonSchema(searchApifyDocsToolArgsSchema) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(searchApifyDocsToolArgsSchema)),
+    annotations: {
+        title: 'Search Apify docs',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args } = toolArgs;
 

src/tools/store_collection.ts

@@ -112,6 +112,11 @@ Returns list of Actor cards with the following info:
 `,
     inputSchema: zodToJsonSchema(searchActorsArgsSchema) as ToolInputSchema,
     ajvValidate: ajv.compile(zodToJsonSchema(searchActorsArgsSchema)),
+    annotations: {
+        title: 'Search Actors',
+        readOnlyHint: true,
+        openWorldHint: false,
+    },
     call: async (toolArgs: InternalToolArgs) => {
         const { args, apifyToken, userRentedActorIds, apifyMcpServer } = toolArgs;
         const parsed = searchActorsArgsSchema.parse(args);

src/utils/tools.ts

@@ -10,6 +10,7 @@ export function getToolPublicFieldOnly(tool: ToolBase) {
         name: tool.name,
         description: tool.description,
         inputSchema: tool.inputSchema,
+        annotations: tool.annotations,
     };
 }