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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, covering the safety profile. The description adds genuinely useful conditional behavior (a version that would reject already-placed instances is reported and the old version kept), but 'reload/update' sits in mild tension with a read-only hint and no persistence semantics are clarified.

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?

Three tight sentences with the trigger condition front-loaded ahead of the behavior and return value. Every clause carries information, with only minor redundancy between the title and the opening clause.

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 one-parameter tool with no output schema, the description usefully covers the return value ('the updated scene and what was reloaded') and the failure branch (old version kept), which compensates for the missing output schema. The nested 'scene' object's internal shape is left to the schema.

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 description coverage is 100% with a single required 'scene' parameter, so the schema already documents the only input. The description adds no syntax or format detail for 'scene' beyond what the schema states, 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: reload the families of a scene from the library, explicitly analogized to Revit's 'Reload Family'. It is easy to distinguish from siblings like cao_familles or cao_famille_essayer because it names the exact action (move to latest version).

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?

Opens with an explicit WHEN condition (scene uses library-placed families AND the library has newer versions), which is strong triggering guidance. It does not, however, name alternative tools (e.g. cao_famille_essayer or cao_bibliotheque_familles) or state when NOT to use it.

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