calculate_with_lump_sum

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

With no annotations, the description carries the burden and does well: it explains that the lump sum reduces the outstanding balance at the specified month, that the same monthly payment is retained, and that the result is a shorter loan term. It does not cover edge cases (e.g., lump sum exceeding remaining balance, prepayment penalties, or how a partial final payment is handled).

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 with the purpose and mechanism before the Args/Returns listing; every line carries information. The docstring-style Args/Returns formatting is slightly verbose given an output schema already exists, but nothing is wasted.

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 6-required-parameter calculation tool with no annotations but with an output schema, the description covers the mechanics and every parameter. It omits error/edge-case behavior (invalid month, lump sum larger than balance), which is the only notable 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?

Schema coverage is 0%, so the description must compensate, and it documents all six parameters with units and conventions: dollars, annual percentage, years, and notably that month_to_apply is 1-based. This is meaningfully more than the bare schema titles provide.

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 states a specific verb and resource ('Calculate the amortization schedule') and scopes it to the one-time lump sum case, which implicitly separates it from calculate_with_extra_payments and get_amortization_schedule. It does not explicitly name the sibling it contrasts with, so it falls short of a 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 scenario is described (one-time lump sum applied at a specified month), which implies when this tool applies, but there is no explicit when-to-use/when-not guidance or routing to calculate_with_extra_payments for recurring overpayments. Usage must be inferred from the scenario text.

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