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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so safety and determinism are covered. The description adds genuine context that the figures come from 'MRK's verified fee schedule' and that VAT is applied to trustee and agency fees, but it says nothing about the shape of the response (per-line breakdown vs total), rounding, or the AED assumption.

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?

A single front-loaded sentence that leads with what the tool returns and then itemises the fee lines; there is no filler. The inline fee enumeration is long but each element is informative rather than redundant.

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?

For a read-only, idempotent calculator with a fully documented schema and no output schema, the description covers inputs and fee scope adequately. The gap is navigational: without any statement of how results differ from calculate_dld_buying_costs, an agent facing several cost calculators has no basis for choosing.

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% with four well-annotated parameters, so the baseline is 3. The description reinforces the fee-line semantics behind offPlan and includeAgencyFee (via the agency/NOC mentions) but adds no information beyond the schema about loanAed or priceAed constraints.

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 pair ('Itemised one-off costs of buying in Dubai') and enumerates the exact fee components returned (DLD 4% transfer, admin, title deed, trustee fee +VAT, mortgage registration, agency commission +VAT, developer NOC). It does not, however, differentiate itself from the sibling calculate_dld_buying_costs, which overlaps heavily on the DLD transfer fee territory.

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 name and fee list — an agent can infer this is for estimating total purchase transaction costs — but there is no explicit when-to-use or when-not-to-use guidance, and no mention of when to prefer calculate_dld_buying_costs or calculate_mortgage instead. The sibling set contains near-neighbours that go unaddressed.

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