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

With no annotations provided, the description carries the burden of behavioral disclosure. It transparently lists expected outputs and explains the balloon-balance behavior when the term is shorter than amortization, which is useful. However, it does not disclose default behavior when optional fields like termYears, amortizationYears, or interestOnly are omitted, so behavior beyond the happy path remains hidden.

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 a single dense sentence with no wasted words. It front-loads the core purpose, then lists outputs, then adds a helpful illustrative CRE example. Every clause earns its place.

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?

The description is strong on outputs and the key balloon case, but given no output schema and no annotations, it omits important invocation details such as defaults for optional parameters and how the tool behaves when only required fields (loanAmount and rate) are provided. This is a meaningful gap for an agent deciding how to call the tool correctly.

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 only 40%, so the description must compensate. It adds meaning to termYears and amortizationYears by explaining the balloon relationship, and references interest-only behavior. But it does not clarify loanAmount semantics or the effect of omitting optional fields, leaving some parameter meaning to inference.

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 names a specific resource and operation: payment math for a commercial loan, including amortizing and interest-only modes, with concrete output concepts (monthly/annual debt service, total interest, balloon balance). This clearly distinguishes it from siblings like calculate_metrics, size_loan, or compare_loan_offers based on its unique scope.

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 the tool is for payment calculations and highlights the common CRE case of a 10-year term on a 30-year schedule, but it does not explicitly state when to choose this tool over siblings such as calculate_metrics or run_scenario, nor does it provide exclusions or alternatives. Usage context is implied rather than explicit.

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