calculate_mortgage

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

Description adds 'Read-only and deterministic' and 'Does not include insurance, taxes or fees' beyond the annotations (readOnlyHint, idempotentHint, etc.). No contradiction with 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?

Three sentences, front-loaded with core function, then usage, then inputs. No wasted words.

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?

Covers what tool does, parameters, and exclusions. Lacks description of the return format (e.g., output fields structure) since there is no output schema, but this is a minor 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?

Input schema has 100% description coverage. Description restates parameter meanings in natural language but does not add new semantic value beyond the schema.

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?

Description clearly states it calculates fixed monthly payment, total interest, and total cost of a mortgage, with an optional amortization schedule. It distinguishes from siblings like 'calculate_compound_interest' by specifying it's for fixed-rate amortizing loans.

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?

Explicitly says 'Use for home-loan or any fixed-rate amortizing loan questions in any currency' and clarifies exclusions (insurance, taxes, fees). Does not mention when-not-to-use or alternatives, but the context is clear.

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