Server has 15 tools with consistent naming (verb_noun pattern: pcb_drc, sch_erc, jlcpcb_apply_rules) and detailed descriptions in Portuguese. All tools have input schemas with type definitions and parameter descriptions. However, output schemas are not formally documented, responses are inferred from code (e.g., pcb_drc returns {error} or JSON report, but structure not declared). Error handling uses a _guard wrapper that converts McpKicadError to {error: str}, but lacks recovery guidance or error classification. No tool annotations (readOnlyHint/destructiveHint) despite clear risk levels (READ_ONLY vs WRITE). Parameter descriptions are good (72 chars avg baseline met), but some tools lack enum constraints (e.g., jlcpcb_apply_rules profile param accepts string without listing valid profiles in schema). Output field naming is inconsistent: some tools return {outdir}, others {path}, others {version}, forces LLM to parse varied response shapes.

• Add JSON Schema definitions for all tool outputs. Document return types explicitly (e.g., {version: string}, {outdir: string, files: [string]}, {error: string}). Reference in tool descriptions.
• Implement tool annotations: add readOnlyHint=true to kicad_version, pcb_drc, sch_erc, jlcpcb_list_profiles, jlcpcb_show_rules, board_summary; add destructiveHint=true to pcb_export_*, sch_export_*, jlcpcb_apply_rules, jlcpcb_export_*, jlcpcb_fetch_rotations.
• Standardize output field naming. Use consistent keys: {result: {...}} for success, {error: string, code: string, recovery: string} for errors. Include IDs/paths needed for chaining (e.g., pcb_export_gerbers returns {outdir, files: [string]} so agent can reference generated files).
• Add enum constraint to jlcpcb_apply_rules and jlcpcb_show_rules profile parameter. In schema, set enum: ['2layer', '4layer', '6layer', ...] and document in description: 'One of: 2layer (default), 4layer, 6layer, etc. Call jlcpcb_list_profiles() to see all available.'
• Enhance error messages with recovery guidance. Instead of {error: 'File not found'}, return {error: 'File not found: /path/to/file.kicad_pcb', code: 'FILE_NOT_FOUND', recovery: 'Check the path exists and is readable. Use absolute paths or relative to current working directory.'}. Classify errors: retryable (timeout, rate limit), user-fixable (invalid path, missing file), fatal (permission denied).