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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered. The description adds real context beyond that: the Darcy-Weisbach model and the four returned quantities (velocity, Reynolds number, lambda, pressure loss) including units, which matters since there is no output schema. It stops short of noting limitations such as fittings or non-straight pipe segments.

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?

Three short sentences, front-loaded with the action, then the model, then the outputs. Only the 'einfach online' phrase is dead weight.

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 zero-required-parameter calculation tool with no output schema, the description supplies the missing return-value information and names the governing model. All inputs are covered by the schema, leaving only minor gaps such as handling of defaults or validity limits of the model.

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 units and ranges documented for all six parameters, so the schema carries the parameter burden. The description adds nothing about the inputs themselves, which matches the baseline of 3 for a fully documented 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 states a specific verb and resource ('Druckverlust in geraden Rohrleitungen berechnen') and names the underlying model (Darcy-Weisbach), so an agent knows exactly what computation is performed. Sibling tools are opaque bot_NNN identifiers, so no differentiation is possible or expected, which keeps this 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?

There is no guidance on when to use this tool versus alternatives, no prerequisites, and no exclusions beyond the implicit 'gerade Rohrleitungen' scope. 'einfach online' is marketing filler rather than routing guidance.

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