financial_calc

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 meaningfully explains that rates are percentages, that compounding defaults vary by operation (annual for compound_interest/present_value/future_value, monthly for loan_payment), and that roi uses principal and future_value. This adds valuable context beyond the schema, though it omits edge-case behavior like error handling.

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 three sentences, front-loaded with the main purpose, and uses structured formatting for operation names. Every sentence provides useful information without redundancy, making it concise and scannable.

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?

Given that an output schema exists, the description need not explain return values. It covers key behavioral defaults and parameter semantics, making it fairly complete for a calculator tool. Minor gaps remain regarding invalid inputs or boundary behaviors, but these are not critical.

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 50%, and the description helps fill gaps by clarifying the semantics of principal and future_value for roi, and by explaining how rate and periods are interpreted per operation. This compensates for the undocumented parameters and adds meaning beyond the raw 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?

The description clearly states the tool performs financial calculations for interest, loans, and ROI, using a specific verb and resource. This distinguishes it from general math or statistics sibling tools, and the parenthetical enumerates the covered domains.

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 does not explicitly mention when to use this tool versus siblings like npv or irr. It provides operational context (rates are percentages, operation-specific compounding defaults) that implies usage scenarios, but it lacks explicit exclusions or alternatives, so it falls short of full guidance.

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