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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds real domain behavior: the compensation tiers, flat rates for season tickets, and the €4 payout floor. It does not say what the response actually contains (amount only, eligibility flag, currency), so it stops short of fully characterizing behavior.

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?

Two sentences, front-loaded with the verb, and the rule enumeration is dense but each clause (tiers, season-ticket flat rates, payout floor) carries distinct information. It is efficient, though the compressed legal shorthand assumes the reader parses several rules at once.

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 six-parameter calculator with full schema coverage, the description supplies the governing rules that make the numbers interpretable. With no output schema present, it should ideally state what is returned (e.g., a single EUR amount versus a structured eligibility result), which is the one remaining gap.

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% and each parameter is documented in German directly in the schema, so the baseline is 3. The description only marginally reinforces this by referencing 'Pauschalen für Zeitkarten', which maps to the ticket enum, without adding syntax or format detail beyond the schema.

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 opens with a specific verb and resource ('Berechnet die Entschädigung bei Zugverspätung') and pins the legal basis (VO (EU) 2021/782), which cleanly separates it from the bus/flight/ship compensation siblings. An agent can identify the tool without opening the schema.

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 enumerates the triggering thresholds (25% from 60 min, 50% from 120 min) which implies when the tool is relevant, but never states when to prefer it or its siblings, nor any prerequisite or exclusion. Usage is inferable rather than stated.

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