invest_or_prepay_loan

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

No annotations are provided, so the description must disclose behavioral traits. It explains the core comparison logic (post-tax return vs effective loan cost) but does not mention assumptions like constant rates, time horizon, or whether the analysis is one-time or multi-year. More detail would improve transparency.

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 sentences, no unnecessary words, and conveys the core idea efficiently. It could be slightly more structured with bullet points, but it is concise and front-loaded.

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 complexity of the decision and the presence of an output schema, the description covers the high-level purpose but omits details like assumptions, use cases, or limitations. It is adequate but not thorough.

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 schema has no descriptions for parameters (0% coverage), so the description should add meaning. It hints at 'post-tax' and 'effective loan cost', linking to the tax parameters, but does not explicitly describe each parameter or how they influence the calculation. The addition is minimal.

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 compares investing surplus vs prepaying a loan, using post-tax returns and effective loan cost. It distinguishes itself from siblings like compare_loans or calculate_prepayment_savings by focusing on the investment vs prepayment decision, though it could be more explicit about the output.

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?

There is no guidance on when to prefer this tool over alternatives, such as compare_loans or calculate_prepayment_savings. The description implies usage when deciding between investing and prepaying, but lacks explicit context or exclusions.

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