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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely useful behavior beyond them: results are market-wide aggregates reported as median and percentiles, not individual bank offers — a trait that materially shapes how an agent interprets the return value.

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?

Everything is packed into one front-loaded sentence with no filler: the aggregation nature comes first, then the covered rate families, then the one enum exception. It is dense but scannable, and no sentence fails to earn 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?

With an output schema present, return values need no explanation, and the description covers the non-obvious semantics (aggregate vs individual offers, which product maps to which rate set). Only the cross-sibling routing is missing, which is a minor gap for a tool this well-scoped.

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 67%, and the least self-explanatory parameter is the one the description compensates for: the bare enum values mortgage/cash-loan/deposit/savings/bonds are each mapped to a concrete meaning (e.g. mortgage APRC and margin, retail government bond rates). amount and period carry their own schema descriptions in PLN/years-vs-months, so nothing critical is left dark.

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 opens with a specific verb ("Aggregates") and enumerates exactly which rate families are covered: mortgage APRC/margin, cash loan APRC, deposit/savings rates, and retail government bonds. That makes the resource unambiguous. It stops short of differentiating itself from look-alike siblings such as get_credit_market or get_interest_rates, which it easily could have done.

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?

Usage is only implied: "offers currently on the market" signals a current-snapshot tool, and the parenthetical about product "bonds" routes one enum value to a different dataset. There is no explicit when-to-use/when-not and no named alternative among the many overlapping rate/market siblings, so an agent must infer the choice.

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