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

Beyond the read-only annotation, the description reveals key behavioral traits: fixed defaults for gewerbe (10.000 kWh Strom / 30.000 kWh Gas), the mandatory user confirmation ('ist das für dich in Ordnung?'), and the instruction to expose only estimated_annual_kwh, not the derivation. This is essential for correct agent behavior and exceeds what annotations provide.

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 is front-loaded with the core purpose and then delivers the branching rules and output constraints in a compact paragraph. Every sentence contributes actionable information; there is no filler or repetition.

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 tool with branching logic and an output schema, the description covers all necessary operational detail: the two customer-type branches, the energy-type split, the confirmation requirement, and the exact wording of what to present. The output schema handles return-value details, so nothing critical is missing.

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?

With only 40% schema coverage, the description compensates by mapping persons to privat+Strom and living_area_m2 (+ is_altbau) to privat+Gas, clarifying the otherwise undocumented is_altbau. It doesn't cover edge cases like irrelevant parameter combinations, but adds meaningful semantics 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: 'Schätzt den Jahresverbrauch' (estimates annual consumption), and adds the condition 'wenn der Nutzer ihn nicht kennt' (when the user doesn't know it). This clearly distinguishes it from siblings like search_tariffs or quote, since no other tool estimates consumption.

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 explicitly states when to use the tool ('wenn der Nutzer ihn nicht kennt'), giving clear context. However, it does not name alternatives or when-not-to-use conditions, so it stops short of a 5.

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