calculate_rule_of_72

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

With no annotations provided, the description must disclose behavioral traits. It only states the calculation and output fields but does not mention approximations of the Rule of 72, prerequisites, or any constraints (e.g., accuracy for high rates). This is insufficient.

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 extremely concise: two sentences with no unnecessary words. It is well-structured and front-loaded with the core purpose.

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 tool's simplicity (one parameter, clear calculation) and the presence of an output schema (context indicates Has output schema: true), the description covers the essentials. Minor gap: no explanation of the Rule of 72 approximation, but it is a well-known heuristic.

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 100%, so the schema already describes the parameter well. The description mentions the output field 'annual_rate_pct' which hints at the input unit, but adds little beyond the schema definition. Baseline 3 is appropriate.

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's purpose: estimating years to double an investment using the Rule of 72. It mentions the output fields, which adds clarity. However, it does not explicitly differentiate from other financial calculators like compound interest tools that might also compute doubling time.

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?

No explicit guidance on when to use this tool versus alternatives. The suggestion to see list_bundles for related calculators is vague and does not help an agent decide between similar tools (e.g., compound interest calculation).

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