Calculate an indicative mortgage

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

No annotations are present, so the description carries the full behavioral disclosure burden. It does mention a 'bounded schedule page' which hints at paginated output, but it does not disclose whether the operation is read-only, has side effects, requires permissions, or is subject to rate limits. 'Calculate' implies a non-destructive action but not enough transparency.

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 one sentence, tightly packed, and front-loads the core intent ('Calculate one scenario'). It avoids filler and tautology, but it could be slightly more structured with clauses separating the scenario, the rate, and the pagination. Still, it is efficient and easy to read.

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?

Despite an output schema existing, the description is too thin for an 8-parameter tool. It does not explain how the parameters interoperate, what product types exist, or what a 'bounded schedule page' means in practice. An agent would need to guess the semantics of many fields, making this incomplete for correct invocation.

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?

The schema has 0% parameter description coverage, so the description must compensate. It does add some meaning by hinting at 'dated provider rate' (likely rate_date) and 'bounded schedule page' (schedule_limit and schedule_offset), but it leaves six other parameters (principal_eur, term_years, product_type, fixed_rate_years, start_date) completely unexplained, offering weak semantic guidance.

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 says 'Calculate one scenario' which is a clear, specific verb and resource. It also contrasts implicitly with the 'compare_mortgages' sibling by indicating a single scenario, but it doesn't explicitly name or contrast alternative tools, so it stops short of a full 5.

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 usage gates: 'one scenario' suggests a single calculation rather than comparison, and 'using a dated provider rate' implies a prerequisite. However, it does not explicitly state when to use this tool over siblings like compare_mortgages or list_mortgage_products, nor does it provide exclusions or alternative guidance.

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