calculate_compound_interest

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

With no annotations, the description carries the burden of behavioral disclosure. It names a formula, but the formula as written does not actually incorporate monthly deposits, which is misleading. It also does not explain output format, rounding, handling of zero rates, or whether the result is total accumulated value or just interest.

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 short and front-loaded with the core purpose. No filler words are present. However, the formula is incomplete/misleading, so the conciseness comes at some cost to accuracy.

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 tool has four parameters and no output schema, so the description should explain what the returned value represents and how monthly deposits affect the calculation. It does neither, and the formula given is insufficient to guide correct usage. Important context such as currency, rounding, and edge cases is missing.

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 100%, and the schema already documents each parameter, its type, defaults, and constraints. The description adds some value by mapping principal, rate, months, and deposits into a formula, but this mapping is somewhat inaccurate and does not go beyond what the schema already conveys.

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 identifies the operation: calculating compound interest with monthly deposits, and includes the formula. However, it does not explicitly differentiate this tool from closely related siblings like calculate_investment_return or calculate_financing, so it is clear but not fully differentiated.

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 when to use the tool—when compound interest with monthly contributions is needed—but provides no explicit guidance about when not to use it or which sibling tool should be chosen instead. Given the large set of calculator siblings, this lack of routing guidance is a notable gap.

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