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

With no annotations, the description carries the full transparency burden. It discloses that INPS is 'stimato' (estimated), sets the €85k access limit, and cites the legal source. It does not mention edge-case behavior (e.g., exceeding the limit) or error handling, but the nature of the tool as a read-only calculator is clear.

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 two sentences, front-loaded with the core function and variants, followed by the access limit and legal reference. Every word earns its place; no redundancy or fluff.

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 calculator with no output schema, it names the expected outputs (imposta, INPS, netto), states the eligibility limit, and provides source legislation. It lacks explicit output format or detailed error handling, but is sufficient for a well-scoped calculation tool with fully documented parameters.

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?

Input schema coverage is 100% with detailed descriptions for all four parameters, including enum values and conditions (e.g., regime_startup requirements). The tool description adds no per-parameter meaning beyond the schema, 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?

The description uses a specific verb and resource: 'Calcola imposta sostitutiva (5% startup o 15% standard), INPS stimato e netto per il regime forfettario 2026.' This clearly distinguishes it from sibling calculators like calcola_irpef or calcola_inps by naming the exact regime and components.

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?

It explicitly states the access limit ('Limite accesso: €85.000 ricavi') and legal basis, which tells the user when this tool is applicable. However, it lacks an explicit when-not-to-use or direct comparison to alternatives, relying instead on the regime context and sibling names.

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