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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds only that it returns 'COP and seasonal SCOP estimate', which the output schema already conveys. No auth, rate-limit, or edge-case context is provided.

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?

Four short sentences, front-loaded with the core purpose and scope. The trailing bundle pointer is slightly tangential but not wasteful.

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?

The description contradicts the schema on what inputs are required, which is a correctness gap an agent could act on wrongly. Output schema covers returns, but the input mismatch leaves the definition incomplete/inaccurate for correct invocation.

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% (baseline 3), but the description actively misdescribes the inputs: it claims 'heat output kW, electric input kW' while the schema actually takes indoor_temp and outdoor_temp. This conflicting parameter description is misleading rather than additive.

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 (Compute) and resource (heat pump Coefficient of Performance), and 'Use for HVAC efficiency analysis' frames the domain. It is distinguishable from the many generic 'calculate_*' siblings, though it does not name any specific sibling it differs from.

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?

'Use for HVAC efficiency analysis' gives implied context, and 'See list_bundles for related energie calculators' points at discovery. However, there is no explicit when-to-use/when-not or any named alternative among the hundreds of calculate_* tools.

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