improve error handling for tools and server methods #311
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Contributor
yasomaru
commented
Aug 17, 2025
yasomaru
commented
- Fix tool error handling to properly distinguish between protocol errors and tool execution errors
- Return structured JSON-RPC errors directly for protocol-level issues
- Embed regular tool errors in CallToolResult as per MCP specification
- Improve server error responses for unknown prompts and tools
- Add comprehensive tests for both structured and regular error handling
- Fix tool error handling to properly distinguish between protocol errors and tool execution errors - Return structured JSON-RPC errors directly for protocol-level issues - Embed regular tool errors in CallToolResult as per MCP specification - Improve server error responses for unknown prompts and tools - Add comprehensive tests for both structured and regular error handling This change resolves TODO comments about improper error handling and ensures clients can properly handle different types of errors according to the MCP spec. Fixes: #TODO (error handling improvements)
jba
requested changes
Aug 18, 2025
mcp/tool_test.go
Outdated
| // Create a tool that returns a structured error | ||
| structuredErrorHandler := func(ctx context.Context, req *ServerRequest[*CallToolParamsFor[map[string]any]]) (*CallToolResultFor[any], error) { | ||
| return nil, &jsonrpc2.WireError{ | ||
| Code: -32603, // ErrInternal |
Contributor
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Define this one too, same place.
mcp/tool_test.go
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| var wireErr *jsonrpc2.WireError | ||
| if !errors.As(err, &wireErr) { | ||
| t.Fatalf("expected WireError, got %T: %v", err, err) |
Contributor
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%T, %[1]%v
then you only need one arg
- Introduced a constant for CodeInvalidParams to enhance readability and maintainability in error handling. - Updated server methods to use the new constant instead of hardcoded error codes. - Modified tests to validate the use of the new error code constant for structured JSON-RPC errors. This change aims to standardize error handling across the codebase and improve the clarity of error responses.
yasomaru
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to yasomaru/go-sdk
that referenced
this pull request
Aug 28, 2025
…ocol#311) - Fix tool error handling to properly distinguish between protocol errors and tool execution errors - Return structured JSON-RPC errors directly for protocol-level issues - Embed regular tool errors in CallToolResult as per MCP specification - Improve server error responses for unknown prompts and tools - Add comprehensive tests for both structured and regular error handling
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