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

Beyond the readOnlyHint annotation, the description discloses important behavioral details: the Soll/Ist calculation mode depends on the stored business status, and the result contains no input tax and no prior corrections. This gives the agent a realistic picture of what to expect without overstating the tool's capabilities.

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?

Three sentences, each earning its place: the first states the core calculation, the second explains the calculation basis, and the third clarifies exclusions and limitations. The title also adds a key prerequisite ('Konto nötig'). No filler or redundancy.

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 read-only calculation tool with two simple parameters and no output schema, the description covers the essential context: input period, data source, calculation basis, output contents (net/tax amounts with ELSTER keys), and exclusions. There is no missing information that would prevent an agent from invoking it correctly.

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 already fully documents both parameters (von/bis with JJJJ-MM-TT format) at 100% coverage. The description only adds general context about a 'Zeitraum' without enriching the meaning of the individual parameters further. Baseline 3 is appropriate because the schema carries the parameter documentation burden.

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 specifies a clear action ('Rechnet... zusammen') with a defined resource ('Ausgangsrechnungen'), input period, and output substance (Netto-/Steuerbeträge je Steuersatz, ELSTER-Kennziffern). It also explicitly distinguishes itself from a 'fertige Voranmeldung', so an agent can understand what the tool does and what it does not do.

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 description gives clear context: it is for a time period, based on outgoing invoices only, and uses ELSTER keys. It also explicitly excludes input tax and prior-month corrections, which helps the agent avoid using it for those cases. It does not name alternative tools, but no sibling appears to cover the same calculation, so the lack of explicit alternatives is a minor gap.

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