mercari-calculatorCalculate net profit after 10% fee and shipping costs.
| Name | Required | Description | Default |
|---|---|---|---|
| costPrice | No | Cost/purchase price in JPY | |
| salePrice | Yes | Sale price in JPY | |
| shippingCost | No | Shipping cost in JPY |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Input schema / $schemaAdded value: +"http://json-schema.org/draft-07/schema#"Input schema / properties / costPriceAdded value: +{
+ "default": 0,
+ "description": "Cost/purchase price in JPY",
+ "minimum": 0,
+ "type": "number"
+}Input schema / properties / salePriceAdded value: +{
+ "description": "Sale price in JPY",
+ "minimum": 0,
+ "type": "number"
+}Input schema / properties / shippingCostAdded value: +{
+ "default": 0,
+ "description": "Shipping cost in JPY",
+ "minimum": 0,
+ "type": "number"
+}Input schema / requiredAdded value: +[
+ "salePrice"
+]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, but it omits how the 10% fee is applied (e.g., on sale price), whether costPrice is subtracted, and what the output format is. It only states the outcome.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a concise single sentence with the main verb and key inputs front-loaded. No redundant information.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple calculator with 3 params and no output schema, the description is functional but incomplete. It doesn't mention the role of costPrice or the return format, which might be important given the semantic ambiguity of 'net profit'.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so the description adds limited extra value. It does specify the fee rate (10%) not present in schema, but it doesn't clarify the relationship between costPrice, salePrice, and shippingCost.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool calculates net profit after a 10% fee and shipping costs, which distinguishes it from other calculator tools in the sibling list (e.g., yahoo-auction-calculator). It has a specific verb ('calculate') and resource ('net profit').
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance on when to use this tool versus alternatives. The description doesn't mention use cases, prerequisites, or alternative tools, leaving the agent to infer from the tool name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Multiple tools have overlapping purposes, such as bg-remover, bg-remover-pro, pro-matting, and takumi all performing background removal, and upscaler/upscaler-pro being redundant. With 202 tools, an agent may easily select the wrong one despite detailed descriptions.
Most tools use a consistent kebab-case format with descriptive names like pdf-compress, image-resizer, and tax-return-calc. Exceptions like 'takumi', 'pro-matting', and '-pro' suffixes (bg-remover-pro, upscaler-pro) are minor deviations relative to the total.
202 tools is an extreme mismatch for an MCP server, far exceeding the typical 3-15 well-scoped range. The sheer volume makes it unwieldy for an agent to efficiently navigate and select the right tool.
The tool set provides extensive coverage across many domains, including PDF operations (20+ tools), image editing, financial calculations, e-commerce fee estimation, and YouTube utilities. Minor gaps exist in cross-tool integration, but the breadth is highly comprehensive for the apparent purpose.