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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered structurally. The description adds the genuinely useful caveat that results are indicative and subordinate to Eurocode 5 and signed CCTP documents, but says nothing about what is returned or how a scene missing an entrait is handled.

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 verb and resource are front-loaded, and the four axes are packed into one scannable sentence followed by the data shape and the disclaimer. The 'scene : entrait {…}' fragment duplicates structure already conveyed by the EN-SECTION/EN-ASSEMBLAGE labels, so a little trimming is possible.

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 single-parameter, read-only inspection tool with no output schema, the description covers what is checked and the authority caveat. It leaves open what the response contains (per-axis findings? pass/fail?) and what happens when the scene lacks an entrait, which an agent would need before trusting the result.

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 100% schema description coverage and a single nested 'scene' object, the schema already carries the parameter semantics. The description's 'scene : entrait {section, assemblage, appuis, protection}' largely restates the schema description verbatim, so the baseline of 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 (VERIFIER) and a specific resource (l'entrait de ferme), then enumerates the four check axes: section/matériau, assemblage/connecteurs, appuis/portée, protection/traitement. That is far more precise than a sibling like cao_bim_fermes or cao_bim_charpente, though it never names those siblings to explicitly route the 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?

'Appelez quand vous devez VERIFIER L'ENTRAIT' gives a clear triggering condition, and the closing note 'Indicatif — Eurocode 5 et CCTP signés priment' tells the agent the output is advisory rather than normative. No explicit when-not-to-use or named alternative is offered, which keeps it below 5.

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