MCP Documentation Service

Instructions

Implementation Reference

• src/handlers/documents.ts:116-138 (handler)

  The core handler function for the read_document tool. It validates the document path, reads the file content using fs.readFile, extracts frontmatter metadata, and returns a ToolResponse object.

  async readDocument(docPath: string): Promise<ToolResponse> {
    try {
      const validPath = await this.validatePath(docPath);
      const content = await fs.readFile(validPath, "utf-8");
  
      return {
        content: [{ type: "text", text: content }],
        metadata: {
          path: docPath,
          ...parseFrontmatter(content).frontmatter,
        },
      };
    } catch (error) {
      const errorMessage =
        error instanceof Error ? error.message : String(error);
      return {
        content: [
          { type: "text", text: `Error reading document: ${errorMessage}` },
        ],
        isError: true,
      };
    }
  }

• src/schemas/tools.ts:9-11 (schema)

  Zod schema for validating input to the read_document tool. Requires a 'path' parameter specifying the document to read.

  export const ReadDocumentSchema = ToolInputSchema.extend({
    path: z.string(),
  });

• src/index.ts:199-205 (registration)

  Tool registration in the listToolsRequestSchema handler, defining the tool's name, description, and input schema for MCP protocol.

    name: "read_document",
    description:
      "Read a markdown document from the docs directory. Returns the document content " +
      "including frontmatter. Use this tool when you need to examine the contents of a " +
      "single document.",
    inputSchema: zodToJsonSchema(ReadDocumentSchema) as any,
  },

• src/index.ts:311-319 (registration)

  Dispatch logic in the callToolRequestSchema handler that validates arguments using the schema and calls the documentHandler.readDocument method.

  case "read_document": {
    const parsed = ReadDocumentSchema.safeParse(args);
    if (!parsed.success) {
      throw new Error(
        `Invalid arguments for read_document: ${parsed.error}`
      );
    }
    return await documentHandler.readDocument(parsed.data.path);
  }