diff --git a/Cargo.lock b/Cargo.lock
index dbf7c77a..652e6405 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3572,6 +3572,7 @@ dependencies = [
  "tempfile",
  "thiserror 1.0.69",
  "url",
+ "utoipa",
 ]
 
 [[package]]
diff --git a/crates/goose-server/src/openapi.rs b/crates/goose-server/src/openapi.rs
index bcbed312..27282645 100644
--- a/crates/goose-server/src/openapi.rs
+++ b/crates/goose-server/src/openapi.rs
@@ -5,6 +5,7 @@ use goose::agents::ExtensionConfig;
 use goose::config::ExtensionEntry;
 use goose::providers::base::ConfigKey;
 use goose::providers::base::ProviderMetadata;
+use mcp_core::tool::{Tool, ToolAnnotations};
 
 #[allow(dead_code)] // Used by utoipa for OpenAPI generation
 #[derive(OpenApi)]
@@ -32,6 +33,8 @@ use goose::providers::base::ProviderMetadata;
         ExtensionConfig,
         ConfigKey,
         Envs,
+        Tool,
+        ToolAnnotations,
     ))
 )]
 pub struct ApiDoc;
diff --git a/crates/goose/src/agents/extension.rs b/crates/goose/src/agents/extension.rs
index 056786e2..838f8bbe 100644
--- a/crates/goose/src/agents/extension.rs
+++ b/crates/goose/src/agents/extension.rs
@@ -1,6 +1,7 @@
 use std::collections::HashMap;
 
 use mcp_client::client::Error as ClientError;
+use mcp_core::tool::Tool;
 use serde::{Deserialize, Serialize};
 use thiserror::Error;
 use tracing::warn;
@@ -155,7 +156,7 @@ pub enum ExtensionConfig {
         /// The name used to identify this extension
         name: String,
         /// The tools provided by the frontend
-        tools: Vec<mcp_core::tool::Tool>,
+        tools: Vec<Tool>,
         /// Instructions for how to use these tools
         instructions: Option<String>,
     },
diff --git a/crates/mcp-core/Cargo.toml b/crates/mcp-core/Cargo.toml
index d2d613dc..2e7d4cc6 100644
--- a/crates/mcp-core/Cargo.toml
+++ b/crates/mcp-core/Cargo.toml
@@ -13,6 +13,7 @@ anyhow = "1.0"
 chrono = { version = "0.4.38", features = ["serde"] }
 url = "2.5"
 base64 = "0.21"
+utoipa = "4.1"
 
 [dev-dependencies]
 tempfile = "3.8"
diff --git a/crates/mcp-core/src/tool.rs b/crates/mcp-core/src/tool.rs
index 65a954ff..e6d0c2c6 100644
--- a/crates/mcp-core/src/tool.rs
+++ b/crates/mcp-core/src/tool.rs
@@ -2,6 +2,7 @@
 /// Tool calls represent requests from the client to execute one
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
+use utoipa::ToSchema;
 
 /// Additional properties describing a tool to clients.
 ///
@@ -11,7 +12,7 @@ use serde_json::Value;
 ///
 /// Clients should never make tool use decisions based on ToolAnnotations
 /// received from untrusted servers.
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, ToSchema)]
 #[serde(rename_all = "camelCase")]
 pub struct ToolAnnotations {
     /// A human-readable title for the tool.
@@ -100,7 +101,7 @@ impl ToolAnnotations {
 }
 
 /// A tool that can be used by a model.
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, ToSchema)]
 #[serde(rename_all = "camelCase")]
 pub struct Tool {
     /// The name of the tool
diff --git a/ui/desktop/openapi.json b/ui/desktop/openapi.json
index c3b85a5a..6744e2cb 100644
--- a/ui/desktop/openapi.json
+++ b/ui/desktop/openapi.json
@@ -424,6 +424,39 @@
                 ]
               }
             }
+          },
+          {
+            "type": "object",
+            "description": "Frontend-provided tools that will be called through the frontend",
+            "required": [
+              "name",
+              "tools",
+              "type"
+            ],
+            "properties": {
+              "instructions": {
+                "type": "string",
+                "description": "Instructions for how to use these tools",
+                "nullable": true
+              },
+              "name": {
+                "type": "string",
+                "description": "The name used to identify this extension"
+              },
+              "tools": {
+                "type": "array",
+                "items": {
+                  "$ref": "#/components/schemas/Tool"
+                },
+                "description": "The tools provided by the frontend"
+              },
+              "type": {
+                "type": "string",
+                "enum": [
+                  "frontend"
+                ]
+              }
+            }
           }
         ],
         "description": "Represents the different types of MCP extensions that can be added to the manager",
@@ -566,6 +599,63 @@
           }
         }
       },
+      "Tool": {
+        "type": "object",
+        "description": "A tool that can be used by a model.",
+        "required": [
+          "name",
+          "description",
+          "inputSchema"
+        ],
+        "properties": {
+          "annotations": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/ToolAnnotations"
+              }
+            ],
+            "nullable": true
+          },
+          "description": {
+            "type": "string",
+            "description": "A description of what the tool does"
+          },
+          "inputSchema": {
+            "description": "A JSON Schema object defining the expected parameters for the tool"
+          },
+          "name": {
+            "type": "string",
+            "description": "The name of the tool"
+          }
+        }
+      },
+      "ToolAnnotations": {
+        "type": "object",
+        "description": "Additional properties describing a tool to clients.\n\nNOTE: all properties in ToolAnnotations are **hints**.\nThey are not guaranteed to provide a faithful description of\ntool behavior (including descriptive properties like `title`).\n\nClients should never make tool use decisions based on ToolAnnotations\nreceived from untrusted servers.",
+        "properties": {
+          "destructiveHint": {
+            "type": "boolean",
+            "description": "If true, the tool may perform destructive updates to its environment.\nIf false, the tool performs only additive updates.\n\n(This property is meaningful only when `read_only_hint == false`)\n\nDefault: true"
+          },
+          "idempotentHint": {
+            "type": "boolean",
+            "description": "If true, calling the tool repeatedly with the same arguments\nwill have no additional effect on its environment.\n\n(This property is meaningful only when `read_only_hint == false`)\n\nDefault: false"
+          },
+          "openWorldHint": {
+            "type": "boolean",
+            "description": "If true, this tool may interact with an \"open world\" of external\nentities. If false, the tool's domain of interaction is closed.\nFor example, the world of a web search tool is open, whereas that\nof a memory tool is not.\n\nDefault: true"
+          },
+          "readOnlyHint": {
+            "type": "boolean",
+            "description": "If true, the tool does not modify its environment.\n\nDefault: false"
+          },
+          "title": {
+            "type": "string",
+            "description": "A human-readable title for the tool.",
+            "nullable": true
+          }
+        }
+      },
       "UpsertConfigQuery": {
         "type": "object",
         "required": [
diff --git a/ui/desktop/src/api/types.gen.ts b/ui/desktop/src/api/types.gen.ts
index 84716738..4fc3647d 100644
--- a/ui/desktop/src/api/types.gen.ts
+++ b/ui/desktop/src/api/types.gen.ts
@@ -52,6 +52,20 @@ export type ExtensionConfig = {
     name: string;
     timeout?: number | null;
     type: 'builtin';
+} | {
+    /**
+     * Instructions for how to use these tools
+     */
+    instructions?: string | null;
+    /**
+     * The name used to identify this extension
+     */
+    name: string;
+    /**
+     * The tools provided by the frontend
+     */
+    tools: Array<Tool>;
+    type: 'frontend';
 };
 
 export type ExtensionEntry = ExtensionConfig & {
@@ -121,6 +135,75 @@ export type ProvidersResponse = {
     providers: Array<ProviderDetails>;
 };
 
+/**
+ * A tool that can be used by a model.
+ */
+export type Tool = {
+    annotations?: ToolAnnotations | null;
+    /**
+     * A description of what the tool does
+     */
+    description: string;
+    /**
+     * A JSON Schema object defining the expected parameters for the tool
+     */
+    inputSchema: unknown;
+    /**
+     * The name of the tool
+     */
+    name: string;
+};
+
+/**
+ * Additional properties describing a tool to clients.
+ *
+ * NOTE: all properties in ToolAnnotations are **hints**.
+ * They are not guaranteed to provide a faithful description of
+ * tool behavior (including descriptive properties like `title`).
+ *
+ * Clients should never make tool use decisions based on ToolAnnotations
+ * received from untrusted servers.
+ */
+export type ToolAnnotations = {
+    /**
+     * If true, the tool may perform destructive updates to its environment.
+     * If false, the tool performs only additive updates.
+     *
+     * (This property is meaningful only when `read_only_hint == false`)
+     *
+     * Default: true
+     */
+    destructiveHint?: boolean;
+    /**
+     * If true, calling the tool repeatedly with the same arguments
+     * will have no additional effect on its environment.
+     *
+     * (This property is meaningful only when `read_only_hint == false`)
+     *
+     * Default: false
+     */
+    idempotentHint?: boolean;
+    /**
+     * If true, this tool may interact with an "open world" of external
+     * entities. If false, the tool's domain of interaction is closed.
+     * For example, the world of a web search tool is open, whereas that
+     * of a memory tool is not.
+     *
+     * Default: true
+     */
+    openWorldHint?: boolean;
+    /**
+     * If true, the tool does not modify its environment.
+     *
+     * Default: false
+     */
+    readOnlyHint?: boolean;
+    /**
+     * A human-readable title for the tool.
+     */
+    title?: string | null;
+};
+
 export type UpsertConfigQuery = {
     is_secret: boolean;
     key: string;