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

Annotations already declare readOnlyHint=true and idempotentHint=true. The description adds the crucial caveat 'Résultat ESTIMÉ' and specifies that hypotheses (rendement/durée) are provided by the caller, and cites the calculation method. This enriches behavioral transparency beyond the annotations without contradiction.

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 description is front-loaded with the title and purpose, then lists the strategies and outputs. It is a single paragraph with a clear structure, but it includes some redundancy (repeating the title) and could be slightly more concise. Still, every sentence adds value, so it is appropriately sized.

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?

Given the absence of an output schema, the description explicitly states what the tool returns: 'Rend l'effort mensuel et le patrimoine/flux de trésorerie à terme de chaque stratégie.' It also notes the estimation nature and the source of assumptions, covering the essential context an agent needs to call it correctly. No missing critical information.

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%, so parameters are already described. The description adds semantic mapping by naming the three strategies ('tout apporter', 'apport minimal + placement d'un bien secondaire', 'apport minimal + placement financier') which correspond to the nested objects (unique, secondaire, financier). This helps the agent understand which object to populate for each strategy, going beyond the terse 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 clearly states the tool compares three financing strategies for a real estate project, naming each strategy explicitly. It uses a specific verb 'Compare' and identifies the resource (financing of a real estate project), and it is distinct from sibling tools like simulateurs_scpi or fiscal_*.

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 description implies usage context: it is for comparing financing options for a real estate project. It does not name alternatives or provide explicit when-not guidance, but the scope is clear enough that an agent would know when to select it among the many simulateurs_* tools.

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