PAID ($0.005). Historical values of a reference series with effective date ranges, optionally filtered by from/to (YYYY-MM-DD). Pass api_key if you have one; otherwise the response explains how to pay via x402.
| Name | Required | Description | Default |
|---|---|---|---|
| to | No | Latest effective date, YYYY-MM-DD | |
| from | No | Earliest effective date, YYYY-MM-DD | |
| series | Yes | Series id | |
| api_key | No | API key | |
| country | Yes | ISO country code |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It openly discloses the cost ('PAID ($0.005)') and the payment/auth behavior ('Pass api_key if you have one; otherwise the response explains how to pay via x402'). This is valuable behavioral context, though it doesn't mention read-only nature or error handling.
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?
Three concise, front-loaded sentences. The cost warning is first, followed by function and filters, then payment guidance. No fluff or redundancy; every sentence earns its place.
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?
Despite no output schema, the description covers the main functionality, optional filters, and payment behavior. It doesn't detail the response structure or error cases, but for a simple read tool it's sufficiently complete, especially with sibling context.
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%, but the description adds meaning by stating from/to are optional filters ('optionally filtered by from/to') and explaining api_key's role in payment. This goes beyond the schema's field-level descriptions.
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 'Historical values of a reference series with effective date ranges', which specifies what the tool does. It implicitly distinguishes from siblings like get_snapshot or get_series by focusing on historical data, though it doesn't explicitly name alternatives.
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 provides context (paid, optional from/to filters, api_key usage) but does not explicitly compare with other tools or state when NOT to use it. It implies use when historical data is needed but lacks sibling differentiation.
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 operation (check, compute, count, get, list) and a distinct resource (minimum wage, income tax, VAT, working days, holidays, series, settlement). The series tools are clearly differentiated by granularity (list, current, history, snapshot), and compute/check tools apply calculations rather than just returning values.
Most tools follow a consistent verb_noun pattern (check_, compute_, count_, get_, list_), but settlement_date is a noun phrase without a verb, and the verbs vary (check, compute, count, get, list) rather than using a single style. Still, the names are descriptive and predictable.
10 tools is within the ideal 3-15 range, and each tool earns its place by covering a distinct facet of statutory reference data: taxes, compliance checks, calendars, series, and settlement. There is no bloat or sense of missing essential tools.
The surface provides strong coverage: compliance checks (minimum wage, taxes), calendar operations (holidays, working days), series catalog/current/history/snapshot, and settlement dates. Minor gaps include no direct tool for settlement conventions (mentioned only as an external endpoint) and no standalone tax bracket getter, but get_series likely covers some rates and users can infer brackets from compute_income_tax.