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

Annotations already declare readOnlyHint=true and idempotentHint=true, which covers safety. The description adds useful behavioral detail: the 'focus' output context, the specific fields included, and the special no-code top-level behavior. This goes beyond what annotations provide without contradicting them.

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?

One long but information-dense sentence, front-loaded with the main output ('Liefert in focus alle Angaben zu einem Zusatzentgelt'). Every clause earns its place, though splitting into shorter sentences would improve readability slightly.

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 an output schema present, annotations covering read-only/idempotent behavior, and a description that explains both code-present and code-absent behavior, nothing an agent needs to call this tool correctly is missing.

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%: both 'code' and 'year' have explicit descriptions and examples in the schema. The description's no-code behavior note is already captured in the schema ('Leer lassen für die oberste Ebene des Katalogs'), so the description adds no extra parameter meaning.

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 ('liefert') and a specific resource (Zusatzentgelt), and enumerates the exact data returned (Betrag, OPS-Kodes, ICD-Kodes, Fallpauschalen, Fußnoten). It also distinguishes itself from the ze_search sibling by describing direct get-by-code behavior and the no-code catalog fallback.

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?

Clear context is provided: call with a ZE code to retrieve details, or without a code to get the top-level catalog. It does not explicitly mention ze_search as the alternative for finding codes, so the when-not-to-use guidance is only implied, not stated.

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