calculate_rule_of_72

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

Discloses the calculation is approximate and provides the formula. With no annotations, the description carries the burden and does well for a simple tool.

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?

Extremely concise: one sentence plus formula. Front-loaded with 'Rule of 72'. No unnecessary words.

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 low complexity, single parameter, and presence of output schema, the description fully covers purpose and calculation method. No missing context.

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?

The description mentions 'annual_rate' in the formula, but does not specify if it's in percentage or decimal form. For a single parameter with 0% schema coverage, it adds basic meaning but could be more precise.

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 approximates years to double money using Rule of 72, providing a specific verb and resource. It distinguishes from siblings by naming a unique financial rule.

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 guidance on when to use this tool vs alternatives like calculate_future_value or calculate_cagr. The description does not mention exclusions or context for choosing Rule of 72.

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