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

The annotation only signals mutation (readOnlyHint=false), while the description adds that the Leistung remains open until billed, that article-derived price/tax values can be overridden by explicitly provided values, and that each call is reported back individually. The account prerequisite appears in the title but is not restated in the description.

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?

Four short sentences carry the core action, the resulting status, the precedence rule, and the repeated-call behavior without filler. The most important information is front-loaded and every sentence earns its place.

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 write operation with no output schema, the description covers the operation's effect, the open status, price/tax resolution, and the no-batch behavior; parameters are fully documented in the schema. It could be slightly more explicit about the response shape, but the mention that each item is individually reported back gives a reasonable expectation.

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 schema already documents all 10 parameters and the baseline is 3. The description adds valuable cross-parameter semantics: price and tax rate come from the article when given, and explicitly provided values take precedence. This is not stated in the schema and helps the agent decide between artikel, einzelpreis, and ust_prozent.

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 opening verb 'Schreibt' plus resource 'eine erbrachte Leistung auf einen Kunden' names the action precisely, and the categories (Stunden, Material, Pauschalen, Fahrtkosten) clarify scope. The phrase 'bleibt offen, bis sie abgerechnet wird' also distinguishes this recording tool from billing-oriented siblings like leistungen_abrechnen.

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 for when to record a Leistung and explicitly instructs repeated calls for multiple line items because there is no batch mode. It does not name a sibling alternative directly, but the 'offen bis abgerechnet' phrasing implies the later billing step.

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