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 provided, the description carries the full burden. It discloses the $0.005 fee, the optional api_key, and the x402 payment flow, which are critical behavioral details beyond the schema. It stops short of describing response structure or error handling, but the essential traits are covered.
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 sentences, front-loaded with the cost warning, then a clear purpose statement, and payment instructions. Every sentence provides necessary context without wasted words.
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 and no annotations, the description covers the core purpose, the paid nature, payment handling, and optional date filters. It lacks response format details, but for a data retrieval tool with fully described parameters, this is adequate.
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 100%, so the baseline is 3. The description adds little beyond the schema: it mentions from/to YYYY-MM-DD format and the api_key, but these are already documented. It reinforces that from/to are optional, which is inferable from the schema's required fields.
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 that the tool provides 'Historical values of a reference series with effective date ranges', which distinguishes it from sibling tools like get_series or get_snapshot. The verb is implicit but the resource and action are unambiguous.
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 implies usage when historical values with effective dates are needed, but it does not explicitly mention alternatives or conditions for use. No exclusions or comparison to siblings are provided.
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: compliance check, tax computation, VAT breakdown, day counting, holiday retrieval, series value/history/snapshot, catalog listing, and settlement date calculation. Even where underlying data overlaps (e.g., minimum wage as a series), the outputs and use cases are clearly differentiated.
Nine of ten tools follow a clear verb_noun pattern (check_minimum_wage, compute_income_tax, compute_vat, count_working_days, get_public_holidays, get_series, get_series_history, get_snapshot, list_series). The outlier is settlement_date, which uses a noun phrase rather than a verb-based name, though it remains unambiguous and readable.
With 10 tools, the server is well-scoped for its reference-data purpose, covering tax, wages, holidays, working days, series discovery, and settlement dates. Each tool earns its place without redundancy or bloat.
The surface provides comprehensive coverage: discovery via list_series, current/historical data via get_series and get_series_history, a full snapshot, tax computations, wage compliance, public holidays, working day counts, and settlement date calculations. There are no obvious gaps or dead ends for the intended domain.