brc_list_vat_rates

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

No annotations are provided, so the description carries the full burden. It does not explicitly state that the operation is read-only or mention any side effects, auth needs, or rate limits. However, it does highlight the need to cross-reference another tool, which adds behavioral context about dependencies. The description is moderately transparent but lacks basic safety/behavioral disclosures.

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 four sentences. The first sentence immediately states the purpose, followed by important usage details. No unnecessary information, and structure is 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?

Given the tool has no output schema, the description does not explain return fields. However, it provides essential domain context about VAT rate selection and cross-referencing. The key field vatCategoryId is explained, which is critical for correct usage. Slight lack of return format details, but overall complete for a list tool with strong domain guidance.

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 low (43%). The description compensates by explaining the concept of vatCategoryId and its role in distinguishing sales vs purchase rates, which adds meaning beyond the schema. It also suggests using brc_list_vat_categories, aiding understanding of related parameters. However, it does not detail pagination parameters like top, page, skip, pageSize.

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 that the tool lists BRC VAT rates, which is a specific verb+resource. It also provides additional context about VAT categories and distinguishes itself from sibling tools like brc_list_vat_categories and brc_list_vat_types by focusing on rates and their usage context.

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 instructs when to use a sales VAT rate vs a purchase rate, even if percentages match. It also recommends cross-referencing brc_list_vat_categories to group rates, providing clear guidance on the workflow and alternatives.

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