AWS appstream2: Reword MCP tool forwarding docs; clarify IAM StackArn scoping
Summary
Editorial rewording of the MCP tool forwarding overview, an expanded verification step that adds a new item 5 recommending the `mcpforwardingtester` sample script from the aws-samples repository, and reworded IAM guidance noting that `CallForwardedTool` access can be limited to specific stacks with the `StackArn` condition key.
Security assessment
The only security-relevant content is the redescribed IAM statement: the `CallForwardedTool` action can be scoped with the `StackArn` condition key, which documents least-privilege access control for forwarded tool invocation. However, this is a wording-only rewrite of pre-existing guidance rather than a new control, and the other hunks (tool-forwarding description, new testing-script step pointing at a GitHub sample) are non-security editorial changes. No vulnerability, CVE, or exposure is addressed.
Evidence
The IAM action for calling forwarded tools is `CallForwardedTool`. To limit access to specific stacks, use the `StackArn` condition key:
Diff
diff --git a/appstream2/latest/developerguide/agent-access-mcp-server.md b/appstream2/latest/developerguide/agent-access-mcp-server.md index d05e340b3..2c3867610 100644 --- a//appstream2/latest/developerguide/agent-access-mcp-server.md +++ b//appstream2/latest/developerguide/agent-access-mcp-server.md @@ -291 +291 @@ Parameters: `include_cursor` (optional — defaults to `false`). -MCP tool forwarding allows agents to interact with applications and the desktop operating system through direct MCP calls rather than using computer use tools. When you enable tool forwarding, the MCP server forwards tools configured on the WorkSpaces application session to your agent. +With MCP tool forwarding, agents can work directly with applications and the operating system. They make direct MCP calls instead of using computer use tools. When you turn on tool forwarding, the MCP server sends your agent the tools set up on the WorkSpaces application session. @@ -322 +322,3 @@ Field | Required | Type | Description - 4. **Verify tool availability** — If the configuration file is present, the service connects to the MCP servers configured in the file and forwards the tools. The forwarded tools appear when the agent lists its available tools. + 4. **Verify tool availability** — If the file is present, the service connects to the MCP servers listed in the file and forwards their tools. The forwarded tools appear when the agent lists its available tools. + + 5. **Test the configuration** — To confirm that tool forwarding works, run the `mcpforwardingtester` script. You can find it in the [sample-code-for-workspaces-agent-access](https://github.com/aws-samples/sample-code-for-workspaces-agent-access/tree/main/utils/mcpforwardingtester) repository on GitHub. The script tests the MCP setup on your WorkSpace. It reports which tools are ready and flags any issues. @@ -357 +359 @@ The `server-name` is the key from your configuration file. For example, a `get_f -The IAM action for calling forwarded tools is `CallForwardedTool`. You can scope access to specific stacks using the `StackArn` condition key: +The IAM action for calling forwarded tools is `CallForwardedTool`. To limit access to specific stacks, use the `StackArn` condition key: