The JSON-RPC error codes this server answers with.
The four standard ones. MCP adds no codes of its own for what happens here: a tool that fails is
not a protocol error, it is a successful call whose result says isError, which is what lets
an agent read the failure and try something else instead of losing the conversation.
The JSON-RPC error codes this server answers with.
The four standard ones. MCP adds no codes of its own for what happens here: a tool that fails is not a protocol error, it is a successful call whose result says
isError, which is what lets an agent read the failure and try something else instead of losing the conversation.