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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), so the bar is lower, and the description still adds genuinely useful behavioral context: null means the line item is absent from the filing rather than zero, amounts are in PLN, and the call draws down the same quota as 'firma'. It does not state anything about volume of data or pagination for what could be a large item-by-item payload.

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 core purpose and the item-code convention are front-loaded, followed by terse, high-value clarifiers (null semantics, currency, quota cost). It is dense but every clause carries information; the single long opening sentence is the only readability cost.

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 no output schema, the description carries the return-value burden and does so for the most error-prone aspects: item codes, section coverage, null-vs-zero, and currency. What remains unstated is the response envelope (shape of the returned rows) and the volume/range of years per call, which an agent would want before invoking on a large filing.

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% — both krs and year are documented in the schema itself, including the default 'najnowszy' for year. The description adds no parameter-level detail beyond that, so the baseline 3 applies; the null/PLN notes describe the response, not the inputs.

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 states a specific verb and resource: it returns a full financial statement item by item, and enumerates the sections produced (balance sheet, P&L in comparative or calculation variant, cash flows) with the legal item-code convention (e.g. A.II.1.). It implicitly contrasts with the sibling 'finanse', but never names it explicitly, so the differentiation is inferable rather than stated.

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: an agent can infer this is the deep, line-item report versus a summary tool, and the note 'Zużywa pulę jak firma' signals that calls are quota-costly, which discourages casual use. However, no explicit when-to-use/when-not or named alternative (e.g. 'finanse' for aggregates) is given.

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