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

Annotations already declare readOnly/idempotent/closed-world, so the safety bar is low. The description adds genuinely useful context by naming the two returned quantities (heat energy during minimum runtime in kWh and minimum buffer volume in liters), which matters because there is no output schema.

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 computation and followed by the result list; no filler or repetition of schema constraints.

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 read-only pure calculator with full schema coverage, the description supplies the missing piece – what the tool returns. Only the role of the region switch (DIN VDE vs NIN/SIA) goes unaddressed in prose.

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% and each parameter already carries title, unit, range and default, so the description can only restate them. It does name three of the four inputs but never mentions the 'region' parameter (DE/CH standards), leaving that choice entirely to 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 and resource: it computes the minimum buffer-storage volume from heat output, compressor minimum runtime and permitted spread. What it does is unambiguous, though the opaque sibling names (bot_0xx) give no basis for differentiation and the description makes no attempt to position itself against them.

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 statement of when to use this calculator versus alternatives, no prerequisites (e.g. sizing context, standard/region selection), and no exclusions. Usage is only implied by the formula described.

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