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 fully covered by structured data. The description adds one genuinely new behavioral fact: a not-found case returns the literal 'nicht verfuegbar' rather than erroring, which is useful for the calling agent, but nothing else is disclosed.

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?

A single front-loaded sentence with the operation, its parameter, and the fallback value, with no filler. Every clause carries information.

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 one-parameter lookup with rich annotations and no output schema, the definition is close to sufficient, but the quoted 'nicht verfuegbar' return is unexplained (empty result vs. sentinel value) and there is no hint on sourcing the termin_id. These are modest gaps for a tool this simple.

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?

With schema description coverage at 0% for the single parameter, the description does clarify that termin_id is the identifier of a single event, adding some meaning beyond the bare integer type in the schema. It does not specify the identifier format, origin, or validity constraints, so the compensation for the coverage gap is only partial.

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 specific verb and resource ('Liefert einen einzelnen Termin') and the lookup key ('nach termin_id'), which distinguishes it from the plural search sibling termine_suchen. It stops short of naming the sibling explicitly, so the differentiation is inferred from singular vs. plural rather than stated.

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?

Using termin_id implies the tool is for fetching one already-known event, which implicitly contrasts with termine_suchen, but no when-to-use or when-not-to-use guidance is given. There is no statement about where an agent should obtain a termin_id before calling.

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