update agentError constructor

## Description

> Should include a concise description of the changes (bug or feature),
it's
> impact, along with a summary of the solution

## PR Checklist

> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:

- [ ] Make sure you reviewed

[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [ ] Make sure to open an issue as a

[bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose)
  before writing your code! That way we can discuss the change, evaluate
  designs, and agree on the general idea
- [ ] Ensure the tests and linter pass
- [ ] Code coverage does not decrease (if any source code was changed)
- [ ] Appropriate docs were updated (if necessary)
- [ ] Make sure to add `!` if this involve a breaking change

🛠️ Fixes #<issue_number_goes_here>

docs/ALLOYDBADMIN_README.md

@@ -23,6 +23,14 @@ To connect to the database to explore and query data, search the MCP store for t
 
 In the Antigravity MCP Store, click the "Install" button.
 
+> [!NOTE]
+> On first use, the installation process automatically downloads and uses
+> [MCP Toolbox](https://www.npmjs.com/package/@toolbox-sdk/server)
+> `>=0.26.0`. To update MCP Toolbox, use:
+> ```npm i -g @toolbox-sdk/server@latest```
+> To always run the latest version, update the MCP server configuration to use:
+> ```npx -y @toolbox-sdk/server@latest --prebuilt alloydb-postgres-admin```.
+
 You'll now be able to see all enabled tools in the "Tools" tab.
 
 > [!NOTE]

docs/ALLOYDBPG_README.md

@@ -27,6 +27,13 @@ For AlloyDB infrastructure management, search the MCP store for the AlloyDB for
 ## Install & Configuration
 
 1. In the Antigravity MCP Store, click the "Install" button.
+    > [!NOTE]
+    > On first use, the installation process automatically downloads and uses
+    > [MCP Toolbox](https://www.npmjs.com/package/@toolbox-sdk/server)
+    > `>=0.26.0`. To update MCP Toolbox, use:
+    > ```npm i -g @toolbox-sdk/server@latest```
+    > To always run the latest version, update the MCP server configuration to use:
+    > ```npx -y @toolbox-sdk/server@latest --prebuilt alloydb-postgres```.
 
 2. Add the required inputs for your [cluster](https://docs.cloud.google.com/alloydb/docs/cluster-list) in the configuration pop-up, then click "Save". You can update this configuration at any time in the "Configure" tab.
 

docs/BIGQUERY_README.md

@@ -21,6 +21,13 @@ An editor configured to use the BigQuery MCP server can use its AI capabilities
 ## Install & Configuration
 
 1. In the Antigravity MCP Store, click the "Install" button.
+    > [!NOTE]
+    > On first use, the installation process automatically downloads and uses
+    > [MCP Toolbox](https://www.npmjs.com/package/@toolbox-sdk/server)
+    > `>=0.26.0`. To update MCP Toolbox, use:
+    > ```npm i -g @toolbox-sdk/server@latest```
+    > To always run the latest version, update the MCP server configuration to use:
+    > ```npx -y @toolbox-sdk/server@latest --prebuilt bigquery```.
 
 2. Add the required inputs in the configuration pop-up, then click "Save". You can update this configuration at any time in the "Configure" tab.
 

docs/CLOUDSQLMSSQLADMIN_README.md

@@ -23,6 +23,14 @@ To connect to the database to explore and query data, search the MCP store for t
 
 In the Antigravity MCP Store, click the "Install" button.
 
+> [!NOTE]
+> On first use, the installation process automatically downloads and uses
+> [MCP Toolbox](https://www.npmjs.com/package/@toolbox-sdk/server)
+> `>=0.26.0`. To update MCP Toolbox, use:
+> ```npm i -g @toolbox-sdk/server@latest```
+> To always run the latest version, update the MCP server configuration to use:
+> ```npx -y @toolbox-sdk/server@latest --prebuilt cloud-sql-mssql-admin```.
+
 You'll now be able to see all enabled tools in the "Tools" tab.
 
 > [!NOTE]

docs/CLOUDSQLMSSQL_README.md

@@ -24,6 +24,13 @@ For Cloud SQL infrastructure management, search the MCP store for the Cloud SQL
 ## Install & Configuration
 
 1. In the Antigravity MCP Store, click the "Install" button.
+    > [!NOTE]
+    > On first use, the installation process automatically downloads and uses
+    > [MCP Toolbox](https://www.npmjs.com/package/@toolbox-sdk/server)
+    > `>=0.26.0`. To update MCP Toolbox, use:
+    > ```npm i -g @toolbox-sdk/server@latest```
+    > To always run the latest version, update the MCP server configuration to use:
+    > ```npx -y @toolbox-sdk/server@latest --prebuilt cloud-sql-mssql```.
 
 2. Add the required inputs for your [instance](https://cloud.google.com/sql/docs/sqlserver/instance-info) in the configuration pop-up, then click "Save". You can update this configuration at any time in the "Configure" tab.
 

docs/CLOUDSQLMYSQLADMIN_README.md

@@ -23,6 +23,14 @@ To connect to the database to explore and query data, search the MCP store for t
 
 In the Antigravity MCP Store, click the "Install" button.
 
+> [!NOTE]
+> On first use, the installation process automatically downloads and uses
+> [MCP Toolbox](https://www.npmjs.com/package/@toolbox-sdk/server)
+> `>=0.26.0`. To update MCP Toolbox, use:
+> ```npm i -g @toolbox-sdk/server@latest```
+> To always run the latest version, update the MCP server configuration to use:
+> ```npx -y @toolbox-sdk/server@latest --prebuilt cloud-sql-mysql-admin```.
+
 You'll now be able to see all enabled tools in the "Tools" tab.
 
 > [!NOTE]

docs/CLOUDSQLMYSQL_README.md

@@ -26,6 +26,13 @@ For Cloud SQL infrastructure management, search the MCP store for the Cloud SQL
 ## Install & Configuration
 
 1. In the Antigravity MCP Store, click the "Install" button.
+    > [!NOTE]
+    > On first use, the installation process automatically downloads and uses
+    > [MCP Toolbox](https://www.npmjs.com/package/@toolbox-sdk/server)
+    > `>=0.26.0`. To update MCP Toolbox, use:
+    > ```npm i -g @toolbox-sdk/server@latest```
+    > To always run the latest version, update the MCP server configuration to use:
+    > ```npx -y @toolbox-sdk/server@latest --prebuilt cloud-sql-mysql```.
 
 2. Add the required inputs for your [instance](https://cloud.google.com/sql/docs/mysql/instance-info) in the configuration pop-up, then click "Save". You can update this configuration at any time in the "Configure" tab.
 

docs/CLOUDSQLPGADMIN_README.md

@@ -23,6 +23,14 @@ To connect to the database to explore and query data, search the MCP store for t
 
 In the Antigravity MCP Store, click the "Install" button.
 
+> [!NOTE]
+> On first use, the installation process automatically downloads and uses
+> [MCP Toolbox](https://www.npmjs.com/package/@toolbox-sdk/server)
+> `>=0.26.0`. To update MCP Toolbox, use:
+> ```npm i -g @toolbox-sdk/server@latest```
+> To always run the latest version, update the MCP server configuration to use:
+> ```npx -y @toolbox-sdk/server@latest --prebuilt cloud-sql-postgres-admin```.
+
 You'll now be able to see all enabled tools in the "Tools" tab.
 
 > [!NOTE]

docs/CLOUDSQLPG_README.md

@@ -26,6 +26,13 @@ For Cloud SQL infrastructure management, search the MCP store for the Cloud SQL
 ## Install & Configuration
 
 1. In the Antigravity MCP Store, click the "Install" button.
+    > [!NOTE]
+    > On first use, the installation process automatically downloads and uses
+    > [MCP Toolbox](https://www.npmjs.com/package/@toolbox-sdk/server)
+    > `>=0.26.0`. To update MCP Toolbox, use:
+    > ```npm i -g @toolbox-sdk/server@latest```
+    > To always run the latest version, update the MCP server configuration to use:
+    > ```npx -y @toolbox-sdk/server@latest --prebuilt cloud-sql-postgres```.
 
 2. Add the required inputs for your [instance](https://cloud.google.com/sql/docs/postgres/instance-info) in the configuration pop-up, then click "Save". You can update this configuration at any time in the "Configure" tab.
 

docs/DATAPLEX_README.md

@@ -20,6 +20,13 @@ An editor configured to use the Dataplex MCP server can use its AI capabilities
 ## Install & Configuration
 
 1. In the Antigravity MCP Store, click the "Install" button.
+    > [!NOTE]
+    > On first use, the installation process automatically downloads and uses
+    > [MCP Toolbox](https://www.npmjs.com/package/@toolbox-sdk/server)
+    > `>=0.26.0`. To update MCP Toolbox, use:
+    > ```npm i -g @toolbox-sdk/server@latest```
+    > To always run the latest version, update the MCP server configuration to use:
+    > ```npx -y @toolbox-sdk/server@latest --prebuilt dataplex```.
 
 2. Add the required inputs in the configuration pop-up, then click "Save". You can update this configuration at any time in the "Configure" tab.
 

docs/LOOKER_README.md

@@ -21,6 +21,13 @@ An editor configured to use the Looker MCP server can use its AI capabilities to
 ## Install & Configuration
 
 1. In the Antigravity MCP Store, click the "Install" button.
+    > [!NOTE]
+    > On first use, the installation process automatically downloads and uses
+    > [MCP Toolbox](https://www.npmjs.com/package/@toolbox-sdk/server)
+    > `>=0.26.0`. To update MCP Toolbox, use:
+    > ```npm i -g @toolbox-sdk/server@latest```
+    > To always run the latest version, update the MCP server configuration to use:
+    > ```npx -y @toolbox-sdk/server@latest --prebuilt looker```.
 
 2. Add the required inputs for your [instance](https://docs.cloud.google.com/looker/docs/set-up-and-administer-looker) in the configuration pop-up, then click "Save". You can update this configuration at any time in the "Configure" tab.
 

docs/SPANNER_README.md

@@ -21,6 +21,13 @@ An editor configured to use the Cloud Spanner MCP server can use its AI capabili
 ## Install & Configuration
 
 1. In the Antigravity MCP Store, click the "Install" button.
+    > [!NOTE]
+    > On first use, the installation process automatically downloads and uses
+    > [MCP Toolbox](https://www.npmjs.com/package/@toolbox-sdk/server)
+    > `>=0.26.0`. To update MCP Toolbox, use:
+    > ```npm i -g @toolbox-sdk/server@latest```
+    > To always run the latest version, update the MCP server configuration to use:
+    > ```npx -y @toolbox-sdk/server@latest --prebuilt spanner```.
 
 2. Add the required inputs for your [instance](https://docs.cloud.google.com/spanner/docs/instances) in the configuration pop-up, then click "Save". You can update this configuration at any time in the "Configure" tab.
 

docs/TOOLBOX_README.md

@@ -12,10 +12,17 @@ The MCP Toolbox for Databases Server gives AI-powered development tools the abil
 ## Install & Configuration
 
 1.  In the Antigravity MCP Store, click the **Install** button. A configuration window will appear.
+    > [!NOTE]
+    > On first use, the installation process automatically downloads and uses
+    > [MCP Toolbox](https://www.npmjs.com/package/@toolbox-sdk/server)
+    > `>=0.26.0`. To update MCP Toolbox, use:
+    > ```npm i -g @toolbox-sdk/server@latest```
+    > To always run the latest version, update the MCP server configuration to use:
+    > ```npx -y @toolbox-sdk/server@latest```. 
 
-2.  Create your [`tools.yaml` configuration file](https://googleapis.github.io/genai-toolbox/getting-started/configure/).
+3.  Create your [`tools.yaml` configuration file](https://googleapis.github.io/genai-toolbox/getting-started/configure/).
 
-3.  In the configuration window, enter the full absolute path to your `tools.yaml` file and click **Save**.
+4.  In the configuration window, enter the full absolute path to your `tools.yaml` file and click **Save**.
 
 > [!NOTE]
 > If you encounter issues with Windows Defender blocking the execution, you may need to configure an allowlist. See [Configure exclusions for Microsoft Defender Antivirus](https://learn.microsoft.com/en-us/microsoft-365/security/defender-endpoint/configure-exclusions-microsoft-defender-antivirus?view=o365-worldwide) for more details.

docs/en/reference/prebuilt-tools.md

@@ -414,10 +414,10 @@ See [Usage Examples](../reference/cli.md#examples).
         entries.
     *   **Dataplex Editor** (`roles/dataplex.editor`) to modify entries.
 *   **Tools:**
-    *   `dataplex_search_entries`: Searches for entries in Dataplex Catalog.
+    *   `search_entries`: Searches for entries in Dataplex Catalog.
-    *   `dataplex_lookup_entry`: Retrieves a specific entry from Dataplex
+    *   `lookup_entry`: Retrieves a specific entry from Dataplex
         Catalog.
-    *   `dataplex_search_aspect_types`: Finds aspect types relevant to the
+    *   `search_aspect_types`: Finds aspect types relevant to the
         query.
 
 ## Firestore

internal/util/errors.go

@@ -0,0 +1,61 @@
+// Copyright 2026 Google LLC
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package util
+
+import "fmt"
+
+type ErrorCategory string
+
+const (
+	CategoryAgent  ErrorCategory = "AGENT_ERROR"
+	CategoryServer ErrorCategory = "SERVER_ERROR"
+)
+
+// ToolboxError is the interface all custom errors must satisfy
+type ToolboxError interface {
+	error
+	Category() ErrorCategory
+}
+
+// Agent Errors return 200 to the sender
+type AgentError struct {
+	Msg   string
+	Cause error
+}
+
+func (e *AgentError) Error() string { return e.Msg }
+
+func (e *AgentError) Category() ErrorCategory { return CategoryAgent }
+
+func (e *AgentError) Unwrap() error { return e.Cause }
+
+func NewAgentError(msg string, cause error) *AgentError {
+	return &AgentError{Msg: msg, Cause: cause}
+}
+
+// ClientServerError returns 4XX/5XX error code
+type ClientServerError struct {
+	Msg   string
+	Code  int
+	Cause error
+}
+
+func (e *ClientServerError) Error() string { return fmt.Sprintf("%s: %v", e.Msg, e.Cause) }
+
+func (e *ClientServerError) Category() ErrorCategory { return CategoryServer }
+
+func (e *ClientServerError) Unwrap() error { return e.Cause }
+
+func NewClientServerError(msg string, code int, cause error) *ClientServerError {
+	return &ClientServerError{Msg: msg, Code: code, Cause: cause}
+}