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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine context beyond that: the data source (BAG, all insurers), the time scope (next year), and the sort order (cheapest first). It does not cover response shape or how results are truncated by 'limit', but with full annotation coverage this is adequate.

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?

Three dense but purposeful sentences, front-loading what is returned and how it is ordered before the optional parameter caveats. Parenthetical asides carry real meaning (KVG/LAMal, Hausarzt, employer coverage), though the middle sentence is packed with several optional knobs at once.

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 read-only, no-output-schema tool this covers the essentials: data provenance, currency (next year), ordering, and the semantics of the trickiest optional flag. The only omissions are the result limit and a hint at the returned fields, which are minor given annotations carry the safety profile.

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 coverage is 67%, and the description compensates where it can: it expands the model enum into plain-language options ('family doctor hausarzt', HMO, Telmed) and, crucially, supplies the only rationale for accident_cover, which the schema leaves undocumented. Franchise and limit are left to the schema, so the support is useful but not exhaustive.

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 verb+resource (official monthly KVG/LAMal premiums) and pins down the output ordering ('cheapest insurer first') plus the required dimensions (municipality/postcode, age, franchise). No sibling tool offers premium comparison, so the distinction is unambiguous.

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 explains the key decision the user faces on accident cover, advising that employees working 8+ hours a week are usually covered by their employer and can omit it. It also frames model and franchise as supplementary filters, giving clear context for optional inputs, though it does not state exclusions or alternative tools (none exist among this toolset).

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