get_quarterly_vat_summary

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

The description explains it aggregates data and calculates VAT, indicating a read-only operation. Annotations already provide readOnlyHint=true, so the bar is lower; the description adds value by detailing the return structure and the aggregation logic.

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 concise with three sentences: first states purpose and input, second explains aggregation, third gives output structure. No redundant information; all sentences are necessary and well-organized.

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 low complexity (2 params, output schema described) and annotations, the description covers purpose, input range, behavior, and output shape. It lacks error handling or edge cases, but is sufficient for a read-only summary tool.

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 has 0% description coverage, so the description must compensate. It specifies the valid quarter range (1-4), adding semantic clarity missing from the schema, which only defines integer type without constraints.

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 it provides a quarterly VAT summary, specifying that it aggregates invoices and expenses to calculate VAT payable. It differentiates from sibling tools by offering a single-call aggregation instead of manual iteration.

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 explicitly says 'Una sola llamada en vez de iterar manualmente,' advising when to use it as an alternative to manual calls. It does not specify when not to use it or mention alternatives, but the context is clear.

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