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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower; the description instead adds genuinely non-obvious context: what L1 means, that club_required is driven by the breed club's Zuchtordnung, and the caveat that a listed qualzucht_trait does not mean every dog is affected. It stops short of auth/permission or freshness/rate-limit context.

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?

Front-loads the use-case triggers, then layers field-by-field explanations, so the important routing information is first. The fully duplicated German translation is a meaningful chunk of the length, but it plausibly serves a bilingual audience rather than being pure filler.

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?

No output schema exists, so the description must carry return-value semantics — and it does, defining the S–E grade with rationale, hereditary diseases, health tests, club_required, and qualzucht_traits levels. An agent can understand the payload without a response schema.

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% for the single breed_slug parameter and the description adds nothing about it (e.g. that the slug must come from search_breeds, or casing/format rules). Baseline 3 applies when the schema does the lifting.

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?

States a specific verb+resource ('per-breed health data: S–E breeding-health grade, hereditary diseases, health tests') and anchors it with real user-query examples. It is clearly distinguishable from search_breeds/search_breeders, which locate breeds or breeders rather than return health profiles.

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?

Gives explicit trigger conditions ('Use when someone asks how healthy a breed is, which hereditary diseases it has, or which health tests to ask a breeder for') plus sample phrasings. It does not name an alternative tool or state when not to use it, so it stops short of a full when/when-not routing.

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