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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, covering the safety profile. The description adds an example of the calculation and the tax scope, but does not disclose return format, calculation edge cases, or rate update behavior. It adds some value without contradicting annotations.

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 two sentences plus a URL, front-loading a concrete example before listing the tax scope. The example earns its place by illustrating the non-resident premium, but a more direct statement of the action could be even tighter.

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 no output schema, annotations covering safety, and 100% schema coverage, the description gives enough context to invoke the tool correctly. It could clarify the return value (e.g., total stamp duty amount) and which tax applies to which region, but the example and tax names cover most of the gap.

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%, so the schema already documents all four parameters. The description's references to 'first-time, second-home and non-resident rates' loosely map to the buyer and nonResident parameters, but add no syntax or format details beyond the schema. Baseline 3 applies.

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 communicates the tool's purpose through a concrete example and by naming the specific taxes (SDLT, LBTT, LTT) and buyer categories it covers. It does not explicitly compare itself to the sibling land_transfer_tax_calculator, so sibling differentiation is absent.

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?

Usage is implied by the tax names and buyer types, but the description never states when to use this tool instead of alternatives (e.g., land_transfer_tax_calculator or income_tax_calculator). No exclusions or prerequisites are given.

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