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

Annotations already establish readOnly/idempotent/closed-world, so the safety profile is covered. The description adds that results are derived from Wärmebedarf and JAZ and lists the three returned quantities, but it says nothing about the accuracy of the estimate, unit-conversion assumptions, or that inputs are fully optional with defaults.

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 action and followed by the result set; little waste. The output enumeration is slightly list-like but earns its place given there is no output schema.

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?

With no output schema, the description does the necessary work of naming the returned values and their units, and the input schema is fully documented. Minor gaps around estimate assumptions are acceptable for a simple pure calculator with all inputs optional.

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 description coverage is 100% (including the enum for region and min/max bounds), so the schema carries parameter meaning. The description only echoes two inputs (Wärmebedarf, JAZ) and adds no format, interaction, or defaulting guidance 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 names a specific verb (Berechnen) and resource (jährlicher Stromverbrauch und Heizkosten einer Wärmepumpe), and even enumerates the computed outputs. It cannot meaningfully differentiate from siblings since all are opaque bot_XXX names, so it falls just short of a 5.

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?

Use is only implied by the nature of a calculator; there is no explicit statement of when to prefer this tool over another, no prerequisites, and no exclusions (e.g. heat pump types or cases where the estimate is not valid).

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