Diagnose Print Issue

Instructions

Implementation Reference

• src/tools/diagnose-print-issue.ts:9-79 (handler)

  Full handler function that registers the 'diagnose_print_issue' tool on the MCP server. Takes symptom (required) and material (optional) inputs, queries the database for troubleshooting entries, sorts them by material-specificity then probability, and returns formatted results or an error with available symptoms if none found.

  export function registerDiagnosePrintIssue(
    server: McpServer,
    db: Database.Database,
  ): void {
    server.registerTool(
      'diagnose_print_issue',
      {
        title: 'Diagnose Print Issue',
        description:
          'Diagnose a 3D printing problem by symptom. Returns possible causes ranked by probability, with specific fixes for each. Optionally filter by material type for material-specific troubleshooting.',
        inputSchema: {
          symptom: z
            .string()
            .describe(
              'The print issue symptom (e.g., "stringing", "warping", "layer_adhesion", "clogging", "elephant_foot")',
            ),
          material: z
            .string()
            .optional()
            .describe(
              'Material type for material-specific diagnosis (e.g., "PLA", "PETG")',
            ),
        },
      },
      async ({ symptom, material }) => {
        const entries = getTroubleshooting(db, symptom.toLowerCase(), material);
  
        if (entries.length === 0) {
          const available = getAvailableSymptoms(db);
          return {
            isError: true,
            content: [
              {
                type: 'text' as const,
                text: `No troubleshooting data found for symptom "${symptom}". Available symptoms: ${available.join(', ')}`,
              },
            ],
          };
        }
  
        // Sort: material-specific first, then by probability
        const probOrder: Record<string, number> = { high: 0, medium: 1, low: 2 };
        const sorted = [...entries].sort((a, b) => {
          // Material-specific entries first when material is provided
          if (material) {
            const aSpecific = a.material_name ? 0 : 1;
            const bSpecific = b.material_name ? 0 : 1;
            if (aSpecific !== bSpecific) return aSpecific - bSpecific;
          }
          return (probOrder[a.probability] ?? 1) - (probOrder[b.probability] ?? 1);
        });
  
        const header = material
          ? `# Diagnosing "${symptom}" (${material})`
          : `# Diagnosing "${symptom}"`;
  
        const lines = [header, ''];
        for (const entry of sorted) {
          const materialTag = entry.material_name
            ? ` [${entry.material_name}-specific]`
            : '';
          lines.push(`## ${entry.cause}${materialTag}`);
          lines.push(`- Probability: ${entry.probability}`);
          lines.push(`- Fix: ${entry.fix}`);
          lines.push('');
        }
  
        return { content: [{ type: 'text' as const, text: lines.join('\n') }] };
      },
    );
  }

• src/tools/diagnose-print-issue.ts:19-31 (schema)

  Input schema defined inline using Zod. 'symptom' is a required string describing the print issue, 'material' is an optional string for filtering by material type.

  inputSchema: {
    symptom: z
      .string()
      .describe(
        'The print issue symptom (e.g., "stringing", "warping", "layer_adhesion", "clogging", "elephant_foot")',
      ),
    material: z
      .string()
      .optional()
      .describe(
        'Material type for material-specific diagnosis (e.g., "PLA", "PETG")',
      ),
  },

• src/server.ts:50-50 (registration)

  Registration of the tool's register function in the main server creation, passing the server instance and database connection.

  registerDiagnosePrintIssue(server, db);

• src/server.ts:17-17 (registration)

  Import of the registration function in the server module.

  import { registerDiagnosePrintIssue } from './tools/diagnose-print-issue.js';

• src/data/db.ts:307-328 (helper)

  Database helper that queries the 'troubleshooting' table by symptom and optionally by material. Returns rows ordered by probability descending.

  export function getTroubleshooting(
    db: Database.Database,
    symptom: string,
    material?: string,
  ): TroubleshootingRow[] {
    if (material) {
      return db
        .prepare(
          `SELECT * FROM troubleshooting
           WHERE symptom = ? AND (material_name = ? OR material_name IS NULL)
           ORDER BY probability DESC`,
        )
        .all(symptom, material) as TroubleshootingRow[];
    }
    return db
      .prepare(
        `SELECT * FROM troubleshooting
         WHERE symptom = ?
         ORDER BY probability DESC`,
      )
      .all(symptom) as TroubleshootingRow[];
  }