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

Annotations already declare readOnly/non-destructive/closed-world, and the description adds substantial value beyond them: it enumerates the actual computed outputs and, unusually, states hard limits — it NEVER emits Bbio/Cep/DH/Ic and those require the official Th-BCE engine. That safety/scope disclosure is exactly what prevents misuse.

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?

Front-loaded with the WHEN clause and dense but purposeful enumerations of computed quantities and exclusions. The Bbio/Cep/DH/Ic caveat earns its place; the lever/threshold tail is slightly sprawling 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?

For a 13-param nested tool with no output schema, the description usefully summarizes what is returned (losses, breakdowns, design levers) and what is not, compensating for the missing output schema. Input semantics are fully delegated to the schema, which is acceptable at 100% coverage.

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% across 13 parameters with rich nested descriptions, so the schema carries the parameter burden. The description adds no parameter-level guidance (units, frame, required fields) beyond what the schema already documents, so the baseline 3 applies.

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 — computes thermal sanity-check indicators (envelope areas, U-values, H_T, ventilation/glazing losses) from the CAO scene — and explicitly bounds what it does NOT produce (Bbio, Cep, DH, Ic). An agent can tell this apart from regulatory or quantity tools without opening the schema.

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?

The 'WHEN' clause gives clear pre-conditions (early thermal sanity check before the official RE 2020 study) and states when-not to rely on it (official figures need Th-BCE + a consultant). It routes conceptually but does not name a sibling tool (e.g. cao_energie) as the alternative, so context is clear yet alternatives are implicit.

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