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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so safety is covered. The description adds real value beyond them: it discloses the 15% tax netting in the returned yield and, importantly, that banks failing the amount limits are surfaced separately in outside_limits rather than silently dropped.

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 ranking criterion and net-yield rule are front-loaded in the first sentence, and the optional-parameter semantics follow compactly. The bilingual glosses and duplicate examples add slight bulk but each clarifies a term an agent would otherwise have to guess.

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 and annotations covering safety, the description only needs to explain the ranking model and option effects, which it does. The outside_limits behavior is called out precisely so the agent can interpret results correctly.

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 baseline is 3, but the description earns extra by interpreting the parameters: it glosses need_early_withdrawal as withdrawal 'without the bank's consent' and supplies two intent-to-argument examples (amount=200000, term_months=12; term_months=3, client='new') that show how a user query becomes a call.

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?

Opens with a specific verb and resource ('Rank Czech term deposits... by the rate'), states the ranking criterion and the net-of-15%-tax yield. This clearly separates it from hlidac_compare_savings, which covers a different product class, so an agent can pick correctly without opening the schema.

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 gives concrete selection conditions for the optional parameters (only count new-client offers with client='new', drop promotions, require early withdrawal) and two worked query examples that map natural language to arguments. It does not explicitly contrast itself against the savings sibling, so it is strong context rather than full when/when-not routing.

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