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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds only the word 'estimate', which hints at an approximate calculation, but says nothing about computational assumptions, return units, or whether results are in watts or kilowatts. Given the annotation coverage, the description adds minimal behavioral context.

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?

The description is a single, grammatically complete sentence with no filler or redundant information. It is appropriately front-loaded and every word contributes to the core purpose.

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 unannotated parameters and no output schema, a one-sentence description is materially incomplete. It does not explain the expected output, the mathematical model, or how this tool fits with the ten sibling tools, making it hard for an agent to call it correctly in isolation.

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 schema description coverage at 0%, the description must compensate for the bare parameter schema, but it does not. While the parameter names (area_m2, u_value_w_m2k, delta_t_k) are somewhat self-explanatory, the description does not confirm the relationship (e.g., Q = U * A * ΔT) or define what each parameter represents in the context of envelope transmission heat loss.

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 ('estimate') and a distinct resource ('envelope transmission heat loss'), which clearly identifies the calculation being performed. However, it does not differentiate from closely related siblings like heat_loss_total or ventilation_heat_loss, leaving scope ambiguity for an agent.

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 such as ventilation_heat_loss or heat_loss_total. The description does not state that this tool covers only the conduction component of envelope losses, nor does it exclude scenarios where a different tool would be more appropriate.

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