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

Annotations already declare readOnlyHint=true, idempotentHint=true, and openWorldHint=false, so safety and determinism are covered. The description adds that results include thermal and electrical power and that efficiency is selectable, but it omits any formula, default behavior, or explanation of how the region parameter affects results.

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 three short sentences: purpose first, then a note about the extra efficiency-based output, then the result fields. It is front-loaded and contains no filler, though it could be marginally tighter.

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?

Given a simple, fully documented schema and strong safety annotations, the description is nearly complete. It compensates for the missing output schema by listing the two output quantities. It does not explain the region parameter's effect on results, but the schema describes that parameter explicitly.

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%, and the schema itself documents all four parameters with titles, ranges, defaults, and enum values. The description mentions volume flow and temperature difference, and implicitly the efficiency parameter, but adds no meaning beyond what the schema provides. Baseline 3 is appropriate because the schema does the heavy lifting.

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 clearly states a specific calculation: heating power in kW from volume flow and temperature difference, plus electrical power at a selectable efficiency. It names the output quantities, so an agent knows exactly what the tool does. Sibling differentiation is not possible because all sibling names are opaque, but the purpose itself is unambiguous.

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 calculator versus alternatives, no prerequisites, and no exclusions. The description only states what the tool computes, leaving usage decisions entirely to the agent.

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