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

With no annotations, the description carries the full burden, and it does disclose two meaningful traits: a hard 5-result sample cap and a paid L402 tier for full results. However, it omits the payment/auth flow details, error behavior, and result ordering, leaving significant behavioral gaps for a gated endpoint.

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 tight sentences, with the free-sample limit front-loaded and the paid tier as a second beat. Nearly zero waste, though the '/v1' path fragment is of marginal use to an agent.

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 four-parameter tool with no annotations, no output schema, and 0% schema coverage, the description is too thin. It covers the sample cap and paywall but leaves the filter semantics and the shape of returned tenders entirely undocumented.

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 0% across four parameters, so the description must compensate—yet it only says 'matching filters'. It never explains what 'q' searches, what 'cpv' is (domain jargon for Common Procurement Vocabulary), the format of 'country', or the currency/unit of 'min_value'.

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 UK/EU public tenders') plus an explicit result cap ('up to 5'). The scope is clear enough for an agent to know this is a free, limited search endpoint, though it doesn't mention the filter dimensions themselves.

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 implies usage (free sample searching with filters, full results gated behind L402 payment at /v1) but gives no explicit guidance on when to call this versus other approaches, nor how to pick among the filters. Usage is inferable rather than stated.

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