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

Adds substantial context beyond the annotations: result cap of 20 short cards, that matching covers title, lot names and buyer, that "subject" disambiguates what is procured, that budgets stay in each tender's native currency (AMD taken from the invitation document), and that conversion uses fixed quarterly reference rates while non-covered currencies are skipped. That is real invocation-shaping behavior, not a restatement of readOnly/idempotent hints.

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?

Front-loaded with what the tool is and where it searches, then filters, then output shape, then the budget-currency caveat. Dense but every sentence carries operational information; the multilingual keyword list (government tenders, госзакупки, тендеры) is slightly redundant padding.

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 needn't be spelled out, yet the description still flags the card-level granularity and the "subject" field, which is exactly the context needed to interpret results. Sources, currency behavior, and filter scope are all covered for an 8-parameter tool.

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, and the description earns above it by explaining the currency coupling between minBudget/maxBudget and budgetCurrency and warning that native-currency budgets are not directly comparable across countries. It adds less for the other parameters (q, cpv, countries, limit), which the schema already fully documents.

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 ("Search open public procurement tenders") and names the covered sources (EU TED, Armenia ARMEPS) plus multilingual query support. It implicitly distinguishes itself from get_tender by promising "up to 20 short cards," but never names the sibling or states that detail lookup is a separate call.

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?

Gives clear usage context: free text in English/Russian/Armenian, optional filters for country, CPV/OKPD2, budget and deadline, and an explicit "to compare budgets across countries, set budgetCurrency" instruction. It stops short of stating when not to use it or pointing to get_tender for full record details.

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