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

Annotations already cover read-only, idempotent, non-destructive, and open-world behavior. The description adds useful behavioral context: the HTTP method, per-call cost, and that results are compact rows meant to feed other tools. It does not go into pagination or response limits, but annotations lower the burder needed.

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 description is one focused sentence with a front-loadead method, cost, domain, and resource, followed by a compact parenthetical filter list. Every element earns its place with no redundancy.

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 12-param tool with no output schema, the description covers scope, core filter semantic, cost, and return shape ('compact rows with ids') well enough for an agent to decide and invoke it. It does not spell out exact response fields or pagination behavior, but page/size exist in the schema with defaults, so this is a minor gap.

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?

With only 50% schema description coverage, the description compensates well for the main filters: it adds full-text semantics for q, prefix semantics for cpv and region, NUTS codes, and the type enum values. It omits page, size, and payment-related params, but those are reasonably covered by schema defaults and descriptions.

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 clearly states the tool's job with a specific verb ('Search'), a defined resource ('Spanish public-sector IT/software/cyber procurement'), and a scope ('awards, tenders and contracts'). It also distinguishes itself from sibling detail tools by saying it returns compact rows with ids for the other tools.

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 this is the list/search entry point and that other tools consume the returned ids, but it never explicitly says when to use search_tenders versus get_tender, get_company_awards, or research. This is adequate context but not explicit routing guidance.

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