Fix optional 'content' parameter being marked required in MCP schema

[strela070]

Summary

Fixes #5.

The content parameter on csharp_diagnostics, csharp_hover, csharp_completions, csharp_definition, csharp_references, csharp_symbols, csharp_code_actions and csharp_rename is documented as optional, and EnsureDocumentOpenAsync already falls back to File.ReadAllTextAsync when it is null:

content ??= await File.ReadAllTextAsync(filePath, ct);

However, the parameters were declared as string? content without a default value, and the MCP SDK (AIFunctionFactory) marks parameters without defaults as required in the generated JSON schema — nullability alone is not enough. MCP clients (e.g. Claude Code) were therefore forced to send the full file content on every call, which is wasteful for large files.

Change

• Added = null defaults to all string? content tool parameters
• Added = default to the trailing CancellationToken parameters where required by C# optional-parameter ordering rules

No behavioral change for callers that pass content; callers that omit it now get the documented read-from-disk behavior instead of a schema validation error.

Verification

tools/list schema after the change — content no longer in required for any tool:

csharp_set_workspace      required=['path']
csharp_definition         required=['filePath', 'line', 'character']
csharp_completions        required=['filePath', 'line', 'character']
csharp_code_actions       required=['filePath', 'startLine', 'startCharacter', 'endLine', 'endCharacter']
csharp_references         required=['filePath', 'line', 'character']
csharp_diagnostics        required=['filePath']
csharp_rename             required=['filePath', 'line', 'character', 'newName']
csharp_hover              required=['filePath', 'line', 'character']
csharp_symbols            required=['filePath']

Functional test on a real multi-project solution (macOS arm64): csharp_set_workspace + csharp_symbols without content correctly reads the file from disk and returns document symbols.

🤖 Generated with Claude Code