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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds real behavioral context beyond that: the output is a link plus a process description, the deadline is returned only when the period end is known, and the caller must forward the URL unmodified.

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 audience and purpose, then the return contents and the handling instruction. Slightly padded by the parenthetical English translation of an already-understandable German sentence, but nothing is truly wasted.

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-optional-parameter, read-only tool with no output schema, the description adequately covers what comes back (link, Ablauf, deadline) and the caller's obligation. The 'Ablauf' content is left unspecified, a minor gap rather than a blocker.

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 coverage is 100%, so the baseline is 3, but the description goes further by explaining the functional effect of the optional period_end — supplying it causes the Abrechnungsfrist to be returned. That meaning is not present in the schema text itself.

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 ('Nebenkostenabrechnung erstellen') and enumerates what the tool returns: the NebenkostenPro link, the workflow, and the billing deadline. It is clearly distinguishable from start_bill_check (creating vs checking), though it never names that sibling 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?

It names the target user and the condition of use ('Vermieter und Hausverwaltungen, die eine Nebenkostenabrechnung erstellen müssen') and gives an operational instruction to pass the link on unchanged. It does not state when to prefer it over start_bill_check or other siblings, so guidance is clear but not exclusionary.

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