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

With no annotations, the description carries the disclosure burden. It explains the calculation formula (watts × hours × price × duty cycle) and the outputs (cost per hour/day/month). This is sufficient for a pure calculation tool with no side effects, though it doesn't mention defaults or edge cases.

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 concise and front-loaded, with the key concept in the first sentence. It includes the formula and output periods without fluff. Some redundancy exists due to bilingual repetition, but it remains efficient and readable.

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 simple calculator with no output schema and no annotations, the description is complete: it states the formula, inputs, and outputs. It gives enough context for an agent to invoke correctly and interpret results without needing further explanation.

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 baseline is 3. The description adds value by linking parameters to the formula—identifying auslastung as compressor duty cycle and clarifying that elapsed time is hours per day. This goes beyond the schema's individual descriptions.

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 clearly states a specific purpose: calculating running costs for an air conditioner or any appliance, with a formula. It distinguishes itself from sibling tools like heizleistung_watt and btu_empfehlung, which address other HVAC metrics.

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 provides clear context on when to use the tool (to determine electricity costs of running an appliance) and the core calculation approach. It doesn't explicitly exclude alternatives or compare with siblings, but the intent is unambiguous given the sibling tools are about sizing/heat, not costs.

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