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

Annotations already declare readOnlyHint/destructiveHint=false, and the description usefully adds the qualitative caveat 'Indicatif — dimensionnement ventilation signe prime', which tells the agent the result is not a certified design. The enumerated check codes also reveal what the run inspects. It stops short of explaining the output shape (a list of findings? per-room verdicts?), which is the remaining gap given there is no output schema.

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?

One dense paragraph, front-loaded with the call condition, then the check list, then the input shape, then the caveat — a logical order with no filler. It is compressed to the point of jargon (bare codes, arrow-less field list), but every clause carries information.

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 complex nested-object tool with no output schema, the description covers the trigger, the four check families, the input structure and the indicative-status caveat. What is missing is the return contract (what a finding looks like, how VMC-* codes surface) and behaviour when VMC data is absent from the scene.

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%, but the description goes beyond it: it expands the nested scene shape and supplies the accepted role values (cuisine|sdb|wc|buanderie|seche), which the schema leaves open (no enums), plus the numeric thresholds (45/30/15 m3/h) that make the fields meaningful. This materially upgrades the single parameter beyond its schema text.

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 opens with a specific verb and resource ('VERIFIER LA VMC') and enumerates exactly the four checks performed, each with its own code (VMC-EXTRACTION, VMC-DEBITS, VMC-ENTREE, VMC-EQUILIBRE). An agent knows precisely what this tool audits. It does not explicitly name a neighbouring ventilation tool (e.g. cao_bim_ventilation_naturelle, cao_bim_mep_aeraulique, cao_bim_equilibrage) as the alternative, so the sibling split is implied rather than stated.

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?

'Appelez quand vous devez VERIFIER LA VMC (MEP, arrete ventilation)' gives an explicit trigger condition tied to the regulatory context, which is more than implied usage. There are no exclusions or named alternatives telling the agent when NOT to call it versus the many other BIM HVAC tools.

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