Critical gaps across all three tools. Tool definitions are inferred from code rather than explicitly registered with schemas. No input schemas visible for get_system_info and analyze_dev_flake (both have empty {} input). generate_flake_graph has a minimal schema with only output_format but no type constraint. Descriptions are present but generic (10-50 chars), lacking WHEN/WHY context. No parameter descriptions. No output schemas documented. Error handling exists (SystemAnalyzerError enum) but errors are not actionable for LLMs. Code shows incomplete implementation (system.rs truncated mid-function). Tool registration mechanism not visible in provided source.

• Add explicit JSON Schema to all tools. get_system_info and analyze_dev_flake should declare required parameters (if any) and types. generate_flake_graph should constrain output_format to an enum: ['dot', 'svg'] with description 'Output format for the dependency graph'.
• Expand tool descriptions to 100-200 characters. Example: 'Get information about the running NixOS system, including nix version, current system architecture, and flake configuration. Call this first to understand the system context before analyzing flakes.'
• Add parameter descriptions. For output_format: 'Output format for the dependency graph. Use "dot" for Graphviz format or "svg" for rendered SVG image. Defaults to "dot".'
• Document output schemas in tool descriptions or as separate schema definitions. Example: 'Returns SystemInfo object with fields: nix_version (string), nix_cmd (string), system_flake (string|null), current_system (string|null), store_path (string|null).'
• Make error messages actionable. Instead of generic SystemAnalyzerError, return structured errors with recovery hints: 'Nix not found. Ensure nix is installed and in PATH. Try: which nix' or 'Flake not found in current directory. Run from a directory containing flake.nix.'

Inferred effective spec: <=2025-11-25.

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry