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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely useful behavior beyond that: search returns a pre-computed result when the query contains km and first registration, and only hits are returned so fetch is required for full text.

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-loaded with the verb and resource, then workflow guidance; every sentence carries information. The German content is restated almost verbatim in English, which is deliberate for bilingual users but is still duplication that costs some tightness.

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 single-parameter, annotation-rich search tool with no output schema, the description covers input format, special input behavior, and the follow-up fetch step. It stops short of describing the hit list shape or result limits, a minor gap.

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?

Only one parameter with 100% schema coverage, so the baseline is 3. The description adds real meaning by showing a richer example query ('997 Carrera, 96000 km, 03.2009') and explaining that embedding mileage and a date changes the result type, which the schema description does not convey.

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 and resource ('Sucht Porsche-Wartungspläne ... nach Modell oder Baureihe') with concrete query examples, and notes that a ready calculation is returned when mileage and first registration are present. It routes the agent to fetch for full text, though it does not contrast with the sibling porsche_wartungsplaene or porsche_service_berechnen 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?

Gives clear usage context: search by model/series, and include km plus first registration to get the finished calculation first. It also states the retrieval step ('Treffer mit fetch abrufen'), establishing the search-then-fetch workflow. No explicit when-not-to-use or named alternatives among the other siblings.

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