Kurs średni NBP

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

With no annotations provided, the description carries the full behavioral burden. It helpfully discloses the non-obvious rule that 'dla_faktury' returns the rate from the last business day before the given date, but it does not mention read-only behavior, error cases, or what happens for invalid dates/currencies.

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 sentences, both load-bearing: the first states the core lookup, the second explains the key parameter behavior. It is front-loaded and contains no redundant or filler text.

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?

For a simple lookup with 100% schema coverage and no output schema, the description covers the essential purpose and the key 'dla_faktury' behavior. Minor omissions around error handling and explicit return semantics are acceptable given the schema richness.

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%, so the schema already documents all three parameters. The description adds some meaning for 'dla_faktury' by citing the VAT and cost rationale, but it does not add further semantics for 'data' or 'waluta' beyond the schema.

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 identifies the resource as the average NBP exchange rate from table A, including a special date-handling rule. It is specific enough to distinguish the tool from unrelated NIP/KRS siblings, though it uses a noun phrase rather than an explicit action verb.

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 explains when the 'dla_faktury' parameter applies, citing the VAT and cost rule, which is useful usage context. However, it does not explicitly state when to use this tool versus alternatives, though the sibling tools are unrelated domains.

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