Skip to main content
Glama
xiaobenyang-com

CurrencyAndOil

calculate_barrels_for_usd

calculate_barrels_for_usd

Calculate how many barrels of Brent crude oil can be purchased for a specified USD amount using real-time pricing data.

Instructions

Calculate how many barrels of Brent crude oil can be purchased for a given amount in US Dollars

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
amountYes

Implementation Reference

  • Core handler function that proxies tool execution to remote API https://mcp.xiaobenyang.com/api, using toolName (e.g., 'calculate_barrels_for_usd') in headers and args in body.
    const calcXiaoBenYangApi = async function (fullArgs: Record<string, any>) {
        // 发起 POST 请求
        let response = await fetch('https://mcp.xiaobenyang.com/api', {
            method: 'POST',
            headers: {
                'XBY-APIKEY': apiKey,
                'func': fullArgs.toolName,
                'mcpid': mcpID
            },
            body: new URLSearchParams(fullArgs)
        });
        const apiResult = await response.text();
    
        return {
            content: [
                {
                    type: "text",
                    text: apiResult // 将字符串结果放入 content 中
                }
            ]
        } as { [x: string]: unknown; content: [{ type: "text"; text: string }] };
    };
  • Wrapper handler that prepares args with toolName and calls the core proxy function.
    const handleXiaoBenYangApi = async (args: Record<string, any>, toolName: string) => {
        // 校验aid是否存在
        if (toolName === undefined || toolName === null) {
            throw new Error("缺少必要参数 'aid'");
        }
        // 合并参数
        const fullArgs = {...args, toolName: toolName};
        // 调用API
        return calcXiaoBenYangApi(fullArgs);
    };
  • src/mcp.ts:50-65 (registration)
    Helper function to register a tool with the MCP server, using the generic handler.
    const addToolXiaoBenYangApi = function (
        name: string,
        desc: string,
        params: Record<string, ZodType>
    ) {
        server.registerTool(
            name,
            {
                title: name,
                description: desc,
                inputSchema: params,
            }
            ,
            async (args: Record<string, any>) => handleXiaoBenYangApi(args, name)
        )
    };
  • src/mcp.ts:90-132 (registration)
    Dynamic registration loop: fetches tool list from remote API (mcpId=1777316659852291), builds Zod schemas, and registers each tool (including 'calculate_barrels_for_usd').
    for (const apiDesc of apiDescList) {
        let inputSchema = JSON.parse(apiDesc.inputSchema);
        const zodDict: Record<string, z.ZodTypeAny> = {};
    
        Object.entries(inputSchema.properties).forEach(([name, propConfig]) => {
            let zodType;
            let pt = (propConfig as { type: string }).type;
            switch (pt) {
                case 'string':
                    zodType = z.string();
                    break;
                case 'number':
                    zodType = z.number();
                    break;
                case 'boolean':
                    zodType = z.boolean();
                    break;
                case 'integer':
                    zodType = z.int32();
                    break;
                case 'array':
                    zodType = z.array(z.any());
                    break;
                case 'object':
                    zodType = z.object(z.any());
                    break;
                default:
                    zodType = z.any();
            }
    
            if (inputSchema.required?.includes(name)) {
                zodDict[name] = zodType;
            } else {
                zodDict[name] = zodType.optional();
            }
        });
    
    
        addToolXiaoBenYangApi(
            apiDesc.name,
            apiDesc.description ? apiDesc.description : apiDesc.name,
            zodDict);
    }
  • Dynamic schema builder: converts remote JSON schema to Zod inputSchema for tools.
    Object.entries(inputSchema.properties).forEach(([name, propConfig]) => {
        let zodType;
        let pt = (propConfig as { type: string }).type;
        switch (pt) {
            case 'string':
                zodType = z.string();
                break;
            case 'number':
                zodType = z.number();
                break;
            case 'boolean':
                zodType = z.boolean();
                break;
            case 'integer':
                zodType = z.int32();
                break;
            case 'array':
                zodType = z.array(z.any());
                break;
            case 'object':
                zodType = z.object(z.any());
                break;
            default:
                zodType = z.any();
        }
    
        if (inputSchema.required?.includes(name)) {
            zodDict[name] = zodType;
        } else {
            zodDict[name] = zodType.optional();
        }
    });
Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries full burden but only states the calculation purpose without disclosing behavioral traits. It doesn't mention whether this uses real-time rates, historical data, requires network calls, has rate limits, or what the output format might be, which are significant gaps for a financial calculation tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, well-structured sentence that efficiently conveys the core functionality without any wasted words. It's appropriately front-loaded with the essential information and maintains perfect conciseness for this straightforward tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the financial calculation complexity, lack of annotations, no output schema, and minimal parameter documentation, the description is insufficiently complete. It doesn't explain how the calculation works (e.g., using current exchange rates, fixed formulas), what data sources are used, or what the return value represents, leaving too many unknowns for reliable agent usage.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema has 0% description coverage for the single 'amount' parameter, and the description doesn't add any semantic context beyond implying it's in US Dollars. It doesn't specify units (e.g., whether amount is in dollars, thousands, etc.), valid ranges, or formatting requirements, failing to compensate for the schema's lack of documentation.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the specific verb ('calculate') and resource ('barrels of Brent crude oil') with precise scope ('for a given amount in US Dollars'). It effectively distinguishes from sibling tools like calculate_barrels_for_eur and calculate_barrels_for_rub by specifying the currency context.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage context through 'for a given amount in US Dollars', which helps differentiate it from EUR/RUB variants. However, it doesn't explicitly state when to use this tool versus alternatives like get_brent_usd_rate or provide exclusion criteria, leaving some guidance gaps.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Install Server

Other Tools

Latest Blog Posts

MCP directory API

We provide all the information about MCP servers via our MCP API.

curl -X GET 'https://glama.ai/api/mcp/v1/servers/xiaobenyang-com/CurrencyAndOil'

If you have feedback or need assistance with the MCP directory API, please join our Discord server