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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds genuinely useful scope constraints beyond that: no person data is included, and the entity may be a law firm or central purchasing body acting for the actual contracting authority. It says nothing about response size, aggregation lag, or how much history the awards/winners sections cover.

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?

It is compact and front-loads the resource, but it is a single comma-chained sentence fragment with two stacked parentheticals, which makes it harder to parse than a short verb-led sentence plus a scope clause. Little is wasted, but the structure is run-on rather than crisp.

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 no output schema, the description carries the burden of describing the return payload, and it does so by enumerating the sections returned. Combined with a fully documented single parameter and read-only annotations, an agent has enough to call it correctly; only cross-tool routing against find_organisations remains 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 100% and the single slug parameter is fully documented in the schema, including the URL form. The description adds no syntax or format detail about the slug, so the baseline 3 applies; nothing is lost because the schema already handles it.

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 names the resource (a contracting authority / Vergabestelle) and enumerates precisely what is returned: contact data, platforms, open tenders, recent awards, offers per award, frequent winners, trades, expiring contracts. That is far more specific than the title 'Vergabestelle abrufen', though it is phrased as a noun fragment with no explicit verb and does not distinguish itself from the similarly-organisation-oriented sibling find_organisations.

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 gives one real routing hint: use the contact in the notice when the goal is a specific procedure ('for a procedure use the contact in its notice'), implicitly pointing to get_tender. But it never says when a caller should use this instead of find_organisations, get_company_awards or search_tenders, which is the main ambiguity given the sibling list.

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