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

Annotations already establish the safe-read profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds real value beyond them: the specific FR 5.00% departmental rate assumption and the fact that it returns tax due and effective rate, which the annotations do not convey.

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?

Front-loaded with the verb and framed in one dense paragraph covering purpose, audience, inputs, outputs, and a cross-reference. 'Use for property buyers' is the weakest sentence but the rest earns its place.

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?

An output schema exists so return values need not be described, and annotations cover the safety profile. With only two fully-documented params and a clear country enum, the description supplies enough context to invoke correctly, missing only rate-variation caveats (e.g. non-5% departments).

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% – price and the FR/BE/US/UK/DE enum are fully documented in the schema. The description merely restates the inputs ('property price, country') without adding units, currency behavior, or edge cases, so 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?

States a specific verb and resource ('Compute property transfer tax') and scopes it with concrete detail: FR droits de mutation at the 5.00% departmental rate plus BE/US/UK/DE coverage. This implicitly separates it from annual-tax siblings like calculate_property_tax_fr and from calculate_stamp_duty_uk, though it never names an alternative explicitly.

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?

'Use for property buyers' gives a minimal audience cue, and it cross-references list_bundles for related 'immobilier' calculators. There is no when-not guidance (e.g. one-time transfer tax vs recurring property tax) and no named alternative among the many tax siblings, so usage is only implied.

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