Get Modelo 390 Summary (IVA Annual Recap)

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

Annotations already indicate readOnlyHint=true and idempotentHint=true, so the description doesn't need to reiterate safety. The description adds behavioral context beyond annotations by specifying the exact return content (totals by rate, deductible IVA, balance). No contradictions.

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 brief, with two sentences and an example. It is front-loaded with the core purpose. Every sentence adds value, and there is no wasted text.

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 that the tool has an output schema (context signals), the description does not need to explain return values. It adequately describes the purpose, parameter, and example. For a simple read tool with one parameter, this is complete.

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% for the single parameter 'period'. The description provides an example ('2025') and repeats the format, adding marginal value over the schema definition. Baseline 3 is appropriate.

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 specifies the verb 'Get' and the resource 'Modelo 390 Summary', and explains what it returns (full-year totals by rate, total deductible IVA, annual balance). It also includes an example with period='2025'. This distinguishes it from sibling tools like frihet_modelo_200_summary or get_monthly_summary.

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 does not explicitly state when to use this tool versus alternatives or when not to use it. It only describes the tool's purpose. Given the many sibling summary tools, some guidance on selection would improve this dimension.

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