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

Annotations already declare readOnlyHint=true, so the read-only nature is covered. The description adds 'full breakdown' which hints at the output's detail level, but it does not disclose any edge cases, limitations, or specifics of the calculation beyond what the annotations provide. The description is not contradictory and offers minimal added behavioral context.

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 of nine words, with no wasted wording. It is front-loaded and efficiently communicates the tool's core purpose.

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?

The tool has four input parameters and a moderately complex calculation logic, but the description gives no context about the SDLT rules, thresholds, or how the boolean flags affect the result. Although an output schema exists, the description is too sparse to guide correct invocation without additional documentation.

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 0%, and the description provides no parameter-specific guidance. While the parameter names (price, non_resident, first_time_buyer, additional_property) are somewhat self-explanatory, the description does not explain units (e.g., GBP), how booleans interact, or the effect of each flag. This fails to compensate for the lack of schema descriptions.

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 'UK Stamp Duty Land Tax (SDLT) calculation with full breakdown' clearly states the tool's verb ('calculation') and resource (UK Stamp Duty Land Tax). It distinguishes itself from sibling property tools by naming the specific tax calculation, making its purpose unambiguous.

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 implies use when a UK stamp duty calculation is needed, but it provides no explicit guidance on when to use this tool versus alternatives or when not to use it. No sibling tool is mentioned, and there is no exclusions or prerequisite context.

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