mcp.tools.error.ToolError

This type appears in public signatures. It is not a package entry point.

struct mcp.tools.error.ToolError

Sstruct [source] ¶

A tool-execution failure, reported as isError tool content.

Description#

MCP separates protocol faults (unknown tool, arguments that do not match the schema -- rejected before a tool body ever runs) from failures a tool body discovers itself. Only the first belongs in the JSON-RPC error field; the second is data the model reads and acts on, which is what rmcp::model::CallToolResult::is_error is for. Every helper below builds one of these instead of a raw ErrorData, so a tool signature that returns Result<_, ToolError> cannot surface a tmux or input refusal as a protocol error by construction.

Public, and re-exported at the crate root: a caller that invokes crate::TmuxTools's methods directly, rather than over the wire, gets this type back and needs Self::into_error_data() to read it.