calculate_mortgage_eligibility

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

With no annotations, the description carries the full burden and does substantial work: it discloses the specific rules applied (LTV caps by nationality/first-property status, +2% stress-test buffer, 50% DBR cap). It does not explicitly state that the tool is a pure, side-effect-free computation, but 'Calculates' plus the regulatory detail makes the behavior largely transparent.

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 dense sentence that front-loads the purpose and enumerates the rules computed; nothing is wasted. It is slightly packed for one sentence, but every clause carries regulatory information the agent cannot get from the schema.

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 7-parameter computation tool with no output schema and no annotations, the description supplies the regulatory model needed to understand the inputs and infer the outputs (eligibility, monthly payment, DBR). It stops short of describing the return shape or edge-case handling, but is largely complete.

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 parameter meaning is already documented. The description adds domain context by tying nationality and first-property status to LTV cap tiers, but it does not explain how each input (e.g. otherMonthlyDebtsAED) feeds the DBR or stress-test computation, so it stays at the baseline for fully-covered schemas.

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 (Calculates) and resource (mortgage affordability/eligibility) and names the regulatory regime it implements. It is clearly distinguishable from siblings like calculate_rental_yield and calculate_dubai_fees, which address different financial questions.

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?

No when-to-use or when-not-to-use guidance and no mention of alternative tools. The regulatory framing implies a use case, but the agent is given no routing criteria or prerequisites (e.g. that this is for new mortgage eligibility rather than refinancing).

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