ecb_fx_rates

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations exist, so the description must carry the full behavioral burden. It signals a read-only public official source and the SDMX 2.1 protocol, but omits critical behavior: the lastNObservations default of 5 means a bare call silently returns only five observations per currency, and nothing is said about how that interacts with startPeriod/endPeriod, rate limits, or response shape.

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?

A single front-loaded sentence with no filler, naming the source and protocol up front. It is efficient, though its brevity comes at the cost of the missing operational detail noted elsewhere.

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?

With four optional parameters, no annotations, and no output schema, the description should explain default behavior and output structure. Instead it leaves the agent guessing about what a default call returns and how the period and observation-count parameters combine.

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% for all four parameters, and the description adds almost nothing: it does not explain the date format for startPeriod/endPeriod, the ISO currency-code expectation, or the precedence between lastNObservations and the period range. The 'SDMX 2.1' mention is only a weak hint at period formatting.

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?

States a specific verb and resource: fetching official ECB daily and historical EUR reference exchange rates. This clearly separates it from ecb_convert_invoices (invoice conversion) and ecb_policy_rates_and_inflation (policy rates), though it never names those siblings explicitly.

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?

There is no guidance on when to choose this tool over ecb_convert_invoices or ecb_policy_rates_and_inflation, and no stated preconditions. Usage is only inferable from the resource name.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.