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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false and destructiveHint=false, so the agent knows this is a safe, closed-world read. The description adds useful context about the data's provenance (Garage Kuhn AG service calculator) and its scope (Porsche Schweiz or Deutschland editions), but says nothing about result volume, ordering, or pagination.

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?

The German sentence is front-loaded and information-dense, but the trailing English sentence is a pure restatement of the opening clause and earns little. One clear sentence would have sufficed, making the two-sentence form mildly redundant.

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 simple, zero-required-parameter reference-list tool with no output schema, the description compensates well by naming the returned fields and the data source. Only minor gaps remain (ordering, count, whether the list is exhaustive), which are not critical to correct invocation.

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 enum parameter is fully documented in the schema ("Nur Pläne dieser Baureihe." with enumerated values). The description restates the filter as optional, which is mildly useful, but adds no syntax or semantics beyond the schema, so the baseline 3 applies.

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 (listet) and resource (Porsche-Wartungspläne) and even enumerates the fields returned (Plan-ID, Baureihen, Zeitraum, Herausgeber, Generation, Varianten). It implicitly distinguishes itself from the compute-oriented siblings (porsche_service_berechnen, porsche_service_erinnerung) by being the reference-data lookup, but never names them 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?

"Optional nach Baureihe filtern" tells the agent the filter exists and is optional, and the mention of the service calculator implies the plan IDs feed later lookups. However, there is no explicit statement of when to call this versus porsche_service_berechnen or porsche_service_erinnerung, so usage is only implied.

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