Surtaxe sur les plus-values immobilières — Taxe additionnelle sur les plus-values immobilières nettes imposables supérieures à 50 000 € (barème par tranches). (sources: CGI art. 1609 nonies G)
| Name | Required | Description | Default |
|---|---|---|---|
| plus_value | Yes | Plus-value nette imposable (€). |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the transparency burden. It discloses that the calculation uses a progressive bracket schedule and applies to net taxable capital gains above 50,000 €, with a legal source. It does not explicitly describe the return format, but for a single-number tax calculator this is a minor gap.
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 a single, front-loaded sentence with an explanatory dash, the key threshold, and the legal source. Every element contributes to understanding the tool, with no redundant or filler content.
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 calculation tool with no output schema, the description provides the tax rule, threshold, and legal basis. It only omits an explicit statement of the computed return value, which is minor given how simple and domain-specific the tool is.
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%, and the input schema already defines plus_value as the net taxable capital gain in euros. The description adds context about the 50,000 € threshold and the tax type, but does not materially enhance the per-parameter meaning beyond what the schema provides.
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 identifies the specific resource: the additional tax on real-estate capital gains, with a 50,000 € threshold and a progressive bracket schedule. It also cites the legal source, making it easy to distinguish from sibling fiscal tools such as fiscal_impot_revenu or fiscal_prelevements_sociaux.
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 gives clear context about the applicable tax and its triggering threshold, which is enough for an agent to know this tool handles the real-estate capital-gains surtax. It does not explicitly name alternatives or state when not to use it, but the scope is precise enough for routing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
The tool families are clearly separated by domain prefixes (fiscal, retraite, referentiel), and the descriptions proactively distinguish near-neighbors such as fiscal_tmi vs fiscal_prelevements_sociaux and retraite_estimation vs retraite_pension_totale. Some initial confusion is possible between retraite_pension_regime and retraite_regimes, but the descriptions are detailed enough to resolve it.
Most tools follow a predictable snake_case domain_object pattern: fiscal_*, retraite_*, referentiel_*. The clear outlier is qotien_capacites, which uses a misspelled, non-domain prefix and breaks the otherwise consistent naming scheme.
With 18 tools, the server is heavier than the typical 3-15 sweet spot, though it is organized into recognizable fiscal, retirement, and referential clusters. The count is defensible for a two-domain server, but it begins to feel like a large MCP surface that agents must navigate carefully.
The server covers the main French income-tax and retirement calculation needs: income tax, marginal rate, social levies, CEHR, property capital-gains surtax, pension estimation, multi-regime totals, net pension, buybacks, progressive retirement, and parental surcharge. Minor gaps exist—such as no explicit long-career early-retirement tool and pensions_fournies being referenced rather than exposed as a first-class tool—but agents can work around them.