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strands.tools.mcp.mcp_types

Type definitions for MCP integration.

MCPTransport = AbstractAsyncContextManager[MessageStream | _MessageStreamWithGetSessionIdCallback] module-attribute

_MessageStreamWithGetSessionIdCallback = tuple[MemoryObjectReceiveStream[SessionMessage | Exception], MemoryObjectSendStream[SessionMessage], GetSessionIdCallback] module-attribute

MCPToolResult

Bases: ToolResult

Result of an MCP tool execution.

Extends the base ToolResult with MCP-specific structured content support. The structuredContent field contains optional JSON data returned by MCP tools that provides structured results beyond the standard text/image/document content.

Attributes:

Name Type Description
structuredContent NotRequired[dict[str, Any]]

Optional JSON object containing structured data returned by the MCP tool. This allows MCP tools to return complex data structures that can be processed programmatically by agents or other tools.
metadata NotRequired[dict[str, Any]]

Optional arbitrary metadata returned by the MCP tool. This field allows MCP servers to attach custom metadata to tool results (e.g., token usage, performance metrics, or business-specific tracking information).
Source code in strands/tools/mcp/mcp_types.py 
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class MCPToolResult(ToolResult):
    """Result of an MCP tool execution.

    Extends the base ToolResult with MCP-specific structured content support.
    The structuredContent field contains optional JSON data returned by MCP tools
    that provides structured results beyond the standard text/image/document content.

    Attributes:
        structuredContent: Optional JSON object containing structured data returned
            by the MCP tool. This allows MCP tools to return complex data structures
            that can be processed programmatically by agents or other tools.
        metadata: Optional arbitrary metadata returned by the MCP tool. This field allows
            MCP servers to attach custom metadata to tool results (e.g., token usage,
            performance metrics, or business-specific tracking information).
    """

    structuredContent: NotRequired[dict[str, Any]]
    metadata: NotRequired[dict[str, Any]]

ToolResult

Bases: TypedDict

Result of a tool execution.

Attributes:

Name Type Description
content list[ToolResultContent]

List of result content returned by the tool.
status ToolResultStatus

The status of the tool execution ("success" or "error").
toolUseId str

The unique identifier of the tool use request that produced this result.
Source code in strands/types/tools.py 
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class ToolResult(TypedDict):
    """Result of a tool execution.

    Attributes:
        content: List of result content returned by the tool.
        status: The status of the tool execution ("success" or "error").
        toolUseId: The unique identifier of the tool use request that produced this result.
    """

    content: list[ToolResultContent]
    status: ToolResultStatus
    toolUseId: str