Calculate eBay fees for US, UK, DE, CA, and AU markets, including final value fee and $0.35 payment processing, based on item price and shipping.
Calculate eBay fees for US/UK/DE/CA/AU markets. Final value fee + payment processing $0.35.
| Name | Required | Description | Default |
|---|---|---|---|
| market | No | ||
| shipping | No | ||
| itemPrice | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden of disclosing behavior. It usefully states that the calculation includes a final value fee plus a $0.35 payment processing fee, but it does not clarify whether shipping is included, whether fee rates vary by market, what currency the output is in, or what the return value represents.
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 two short sentences with no filler. The core purpose and market scope are front-loaded, and the fee-composition detail directly follows in the second sentence.
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?
Given no output schema, no annotations, and 0% schema description coverage, the description leaves important gaps: it does not specify the output format, the role of the shipping parameter, or the fee-rate assumptions per market. An agent could not confidently determine the correct inputs or expected result from this description alone.
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 description coverage is 0%, so the description must explain the parameters. It indirectly covers the market enum by listing US/UK/DE/CA/AU, but it does not explain itemPrice, shipping, or how the formula maps to those inputs. This is only minimal compensation for the schema gap.
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 eBay fees and identifies the applicable markets (US/UK/DE/CA/AU). It is specific enough to distinguish eBay from sibling calculators like etsy_fee_calculator or paypal_fee_calculator, though it does not explicitly name a sibling alternative.
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 is given on when to use this tool versus the many sibling calculators, or when another tool would be more appropriate. The market list implies scope but does not help an agent choose between eBay and PayPal or Etsy fee calculations.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.