calculate_monthly_payment

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

No annotations are provided, so the description carries the full burden. It does disclose the return shape ('JSON object with the monthly_payment field') and the meaning of each input, but says nothing about validation boundaries (e.g., zero interest rate), rounding/precision, or error behavior for a pure-computation tool.

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 one-line purpose followed by compact Args/Returns blocks. Everything is readable and nothing is padded, though the Returns line duplicates information the output schema already carries.

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 simple three-parameter computation with an output schema present, the description covers purpose, all inputs, and the result key. The main remaining gap is the absence of any signal about how this base calculation relates to the six sibling tools.

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 0%, so the description must compensate, and it largely does: it documents all three parameters with units and worked examples ('Loan amount in dollars (e.g., 350000)', 'Annual interest rate as a percentage (e.g., 6.5)', 'Loan term in years (e.g., 30)'). It stops short of stating accepted ranges or constraints on those values.

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: 'Calculate the fixed monthly payment for a mortgage.' The scoping word 'fixed' distinguishes it from siblings like calculate_with_extra_payments and calculate_with_lump_sum, but the description never names those alternatives, so the differentiation is implicit rather than explicit.

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?

There is no when-to-use guidance at all. The description does not tell the agent when this base mortgage calculation is appropriate versus get_amortization_schedule, compare_loan_scenarios, or the extra-payment variants, leaving routing entirely to inference.

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