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

Annotations already declare readOnly, idempotent, non-destructive, open-world, so the safety profile is covered. The description adds genuinely useful behavior beyond that: categories are returned 100 at a time ordered by notice count, each carries its notice count, and categoriesTotal reflects all matches. It does not describe ordering or shape of the country/status/sector lists, which is the remaining gap.

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?

Dense but front-loaded: the resource list comes first, then pagination mechanics, then the sector-vs-category preference. Every clause carries information, though the middle sentence is a run-on that mixes input guidance with output-field names and could be split.

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 need not be explained, and the description still helpfully ties inputs to output fields (nextCategoryOffset, categoriesTotal). It is nearly complete for a three-parameter read tool; only the locale parameter and the ordering of the non-category facet lists are unaddressed.

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%, so the description carries the full burden. It does explain categoryQuery with a concrete example ('road construction') and categoryOffset indirectly by mapping it to the output field nextCategoryOffset, but the locale enum is never mentioned, leaving one of three parameters undocumented anywhere.

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 concrete resource – published country IDs, statuses, sectors and category IDs – so an agent can tell this is the facet/lookup tool rather than a tender-search tool. It never names a sibling explicitly, but the resource list is specific enough to separate it from search_public_tenders and get_public_tender without opening a 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?

There is real guidance for choosing between facets ('prefer sectors for broad needs') and for narrowing with categoryQuery, plus how to page with categoryOffset. What is missing is any statement of when to reach for this tool at all versus search_public_tenders or get_public_tender – the routing decision is left implicit.

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