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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds a real behavioral constraint ('up to 100 category IDs') and explains that categoriesTotal counts every match, which is useful beyond the annotations, but it discloses nothing about the 100-cap consequence or how facets are scoped.

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 compact sentences with the returned-facet inventory front-loaded and the parameter hint following. Nothing is padded, though the opening clause reads as a list rather than a clean purpose statement.

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?

An output schema exists, so return-shape detail is not required, and the description adequately covers what facets are available. It falls short on the locale parameter and on routing guidance relative to the many sibling search/list tools, leaving an agent to infer which tool to pick.

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 must carry parameter meaning. It does explain categoryQuery with a concrete example ('road construction') and the meaning of categoriesTotal, but the locale parameter (with its en/de/fr enum) is entirely unexplained in both description and schema.

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 specific verb-plus-resource: it returns facet values (country IDs, statuses, category IDs) for published tenders. That distinguishes it from search_public_tenders and list_public_tender_sources, though it never names a sibling explicitly.

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?

It implies usage by explaining that you pass categoryQuery to find matching categories, which is a usable hint. However, it gives no guidance on when to call this versus search_public_tenders or list_public_tender_changes, and no prerequisites or exclusions are stated.

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