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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds the aggregation scope but does not explain whether 'combine' means a simple sum, how missing/empty components are handled, or anything about output behavior. This is acceptable for a read-only calculation but not rich.

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?

A single compact sentence with no filler. The verb is front-loaded, and the sentence efficiently conveys the tool's purpose and component inputs.

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 tool with three parameters and no output schema, the description provides the core inputs and purpose but leaves the return format, units, and exact calculation semantics implicit. It is adequate for a straightforward calculation tool but not fully complete.

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?

With 0% schema description coverage, the description carries the burden of explaining parameters. It maps ventilation to ventilation_kw and material loads to material_kw, and implies components_kw holds transmission components. However, it does not clarify that ventilation_kw is optional per the schema, and the exact role of components_kw remains somewhat inferred, so compensation is partial.

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 uses a specific verb, 'Combine', and clearly identifies the resource: transmission, ventilation, and optional process/material loads. This distinguishes it from sibling tools like transmission_heat_loss and ventilation_heat_loss, which handle only individual components.

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?

No guidance is given about when to select this tool versus alternatives. It does not mention siblings such as specific_heat_loss or required_heating_power, nor any exclusion conditions, leaving the agent to infer the appropriate use case.

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