VAT budget

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

Annotations already declare readOnlyHint=true, and the description's verb 'Return' aligns with this. However, the description adds no additional behavioral context, such as how period/filter parameters affect the returned figure or that the tool is read-only. This is consistent with the annotations, so no contradiction, but the value added is minimal.

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, concise sentence that immediately states the tool's purpose. It contains no superfluous words or redundant information, making it efficient and front-loaded.

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?

With 6 parameters (including a multi-enum 'type' and filter/period/frequency modifiers) and no output schema, the description is too terse. It does not explain how the parameters interact, what the returned 'budget VAT figure' represents, or what format the result takes. This is a minimal but under-specified description for a moderately complex 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 description coverage is 100%, and the description adds no parameter-specific details beyond what the schema already provides. The baseline of 3 applies because the schema fully documents each parameter, including enums and examples, so the description is not required to compensate.

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 ('Return') and a specific resource ('budget VAT figure') scoped to 'VAT code or VAT group.' This clearly distinguishes it from sibling tools like banana_vat_balance (VAT balance) and banana_vat_projection (VAT projection) by the 'budget' qualifier.

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 no guidance on when to use this tool versus alternatives such as banana_vat_balance or banana_budget. It does not state exclusions, prerequisites, or typical scenarios. The only implicit usage is that it returns budget VAT figures, but no comparison or selection criteria are provided.

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