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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine behavioral context beyond that: the output of aggregation is explicitly 'quantitatif + cout cumules', which tells the agent this is a computed, non-mutating roll-up. It does not say what an empty scene or scenes set returns.

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?

A single sentence with the trigger condition front-loaded and no filler. The parenthetical lot list is dense but informative; the aggregation clause is slightly compressed into the same breath, making it a run-on rather than maximally scannable.

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?

No output schema exists, and with two nested-object parameters at 0% schema coverage the description should say more about what shape 'scene'/'scenes' take and what one must pass. For a compute tool with mutually alternative inputs, the definition is adequate but leaves a real gap an agent would hit on first call.

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 0% and both parameters are undocumented nested structures, so the description carries the burden. It implicitly maps the singular 'une scene' to one parameter and 'plusieurs batiments' to the plural aggregation parameter, but never names 'scene' vs. 'scenes' or states that at least one must be supplied (required is empty).

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 names a specific verb and resource ('decouper un chantier', 'repartir les elements d'une scene en lots') and clearly enumerates the two operating modes (lot decomposition vs. multi-building aggregation). It does not name any sibling such as cao_revue_lots, so the agent must infer differentiation from the mode description alone.

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 decouper un chantier' gives an explicit trigger condition, and the two modes (split vs. aggregate) tell the agent which situation maps to which behavior. It stops short of stating exclusions or naming the alternative tool when lot review rather than lot creation is wanted.

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