loan_calculator

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

With no annotations, the description carries the full burden, but it discloses almost nothing beyond the basic calculation. It does not state assumptions (e.g., interest compounding method, amortization), edge cases, or that it is a pure read-only calculation. An agent cannot anticipate limitations or side effects.

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 two short sentences with no wasted words, which is structurally clean. However, it is so sparse that it borders on under-specification rather than being appropriately concise. It could be slightly expanded without losing efficiency.

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 the absence of annotations, an output schema, and parameter descriptions, the tool is seriously under-specified. An agent would not know the return format (e.g., numeric payment amount), any constraints on inputs (e.g., positive values), or the underlying formula. This is insufficient for reliable invocation.

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. It lists the three inputs and notes annualRate is in percent, but it does not define principal (currency units?) or years (integer or decimal?), nor explain the relationship between parameters. This adds minimal meaning beyond the parameter names.

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 computes a fixed-rate loan's monthly payment, naming the resource (loan) and the output (monthly payment). It is specific enough to distinguish it from fee calculators, but it does not explicitly differentiate from the sibling mortgage_calculator, which could be seen as overlapping.

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 gives no guidance on when to use this tool versus alternatives. It does not mention conditions like 'use for fixed-rate loans only' or compare with mortgage_calculator or compound_interest_calculator. The context is implied but not explicit.

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