settlement_estimateEstimate converting a USDC amount to EUR via AsterPay's EUR off-ramp. Returns the exchange rate, AsterPay fee (0.5% + €0.10 on the EU rail), net EUR amount and SEPA Instant timing. Input: a USDC amount. Free, read-only — no payment is made.
| Name | Required | Description | Default |
|---|---|---|---|
| amount | Yes | USDC amount, human-readable like '100' or '5.0' |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already mark readOnly, and the description reinforces with 'Free, read-only — no payment is made.' It also discloses the fee formula (0.5% + €0.10) and the EU rail detail, adding valuable behavioral context beyond the annotations.
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?
Two concise sentences cover purpose, outputs, input, and safety, with no extraneous content. Every sentence earns its place, and the structure is front-loaded with the core action.
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?
The description covers return values (rate, fee, net, timing) and the fee structure, which is critical given no output schema. For a simple one-parameter tool with strong annotations, this is complete and actionable.
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?
The input schema fully documents the 'amount' parameter with a human-readable format, and the description repeats 'Input: a USDC amount.' With 100% schema coverage, the description adds minimal extra parameter semantics, so the baseline of 3 is appropriate.
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 estimates USDC→EUR conversion via AsterPay's EUR off-ramp, with specific outputs (exchange rate, fee, net EUR, SEPA timing). This distinguishes it from siblings like market_rates, which likely provide rates without the settlement fee breakdown.
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?
The description says 'Estimate converting a USDC amount to EUR' and 'Input: a USDC amount,' which clearly indicates when to use it. It does not explicitly name alternatives or exclusions, but the context is unambiguous for settlement estimation.
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.
Each tool targets a distinct aspect of the payment domain: trust assessment, market rates, merchant resolution, and settlement estimation. No overlap in purpose, so an agent can easily select the right tool.
All tool names use lowercase with underscores, but they mix verb-first (check_agent_trust) and noun-first (merchant_resolve) patterns. The style is consistent and readable, though not strictly verb_noun throughout.
With 4 tools, the server is well-scoped for a focused payment pre-flight API. Each tool earns its place and the count is within the ideal range.
The tools cover pre-payment information needs (trust, rates, merchant endpoints, estimates) but lack any actual payment execution or account management functionality. This is a notable gap for a settlement service, though the read-only nature is clearly stated.