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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, so the safe pure-calculation profile is covered. The description adds real value by enumerating the three concrete results and their units (kg, kN/m², %), which matters because there is no output schema. It stops short of stating assumptions (e.g. which norm governs ballast values), which is the only remaining gap.

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: the first gives the computation and the comparison, the second lists results with units. No filler, and the core operation is front-loaded.

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 calculation tool with no output schema and no required inputs, the description is complete enough: it names the outputs and their units so the agent knows what comes back, and all inputs are fully documented in the schema. What is missing is any note on the normative assumptions behind the calculation, which would help interpret edge results.

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% with titles, units, ranges and defaults for all six parameters, so the schema does the heavy lifting. The description only implicitly touches parameters via 'je Modulfeld' and 'zulässige Lastreserve' and adds no syntax or interpretation 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?

States a specific verb (berechnet) and resource (Flächenlast einer ballastierten PV-Anlage auf dem Flachdach je Modulfeld) plus the comparison against the roof's load reserve. The three returned quantities are named with units. It does not differentiate itself from any sibling, but the sibling list is opaque IDs so no differentiation is possible from the name alone.

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 says what is computed but never when to use this tool, when not to, or what alternative exists for related roof/PV calculations. An agent must infer the trigger (ballasted flat-roof PV load check) from the purpose sentence alone.

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