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

Beyond the annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=false), the description discloses partial-update behavior, the exclusion of status changes, and a conditional side effect: assigned employees may receive a push notification on a real appointment shift, while the customer receives nothing. This is genuinely useful behavioral context not captured by annotations.

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 description consists of two compact, information-dense sentences. The first front-loads purpose and scope; the second adds the side-effect warning. There is no filler and nothing repeats the annotations or schema.

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 mutation tool with no output schema and moderate schema coverage, the description sufficiently covers the key behavioral semantics (partial update, no status change, notification side effects). It reasonably relies on the schema for the date format and idempotency workflow. A minor gap is the lack of any mention of the return value or confirmation, but that is not critical given the annotations.

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?

The schema covers 57% of parameters, and the description adds meaning by mapping 'Titel, Beschreibung, Ort oder Termin' to the relevant fields and explicitly stating that only supplied fields are touched. This partial-update semantics is not evident from the schema alone. The idempotency_key behavior is already thoroughly documented in the schema, so no duplication is needed.

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 uses the specific verb 'Ändert' (changes) and names the exact resource ('bestehenden Auftrags') plus the fields affected: Titel, Beschreibung, Ort, Termin. It also adds scoping constraints ('Nur die angegebenen Felder werden angefasst', 'Ändert NICHT den Status'), which clearly distinguishes it from create/view/search siblings.

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?

The first sentence clearly implies the tool is for modifying existing order fields, and the explicit 'Ändert NICHT den Status' provides a when-not boundary. However, it does not name alternative tools (e.g., auftrag_anlegen for status changes or new orders), so it stops short of full alternative routing.

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