debt_payoff_plan

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

The annotations already declare readOnlyHint=true, so the agent knows this is a calculation-only tool with no side effects. The description adds useful behavioral context about what the tool compares (base vs. extra payments) and what outputs to expect (months and dollars saved), but doesn't provide additional behavioral details like calculation methodology, assumptions, or limitations.

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 perfectly concise with two sentences that each earn their place. The first sentence states the core purpose, and the second sentence adds valuable comparative context. No wasted words, and the information is front-loaded effectively.

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 that this tool has complete schema descriptions (100% coverage), readOnlyHint annotation, and an output schema (implied by context signals), the description provides exactly what's needed. It explains the tool's purpose and comparative nature without needing to repeat parameter details or output format information that's already available in structured fields.

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?

With 100% schema description coverage, all parameters are already well-documented in the input schema. The description adds minimal additional semantic context by mentioning 'base payment plan vs adding extra monthly payments' which relates to the extra_monthly parameter, but doesn't provide significant value beyond what's in the structured schema.

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 with specific verbs ('calculate', 'compares') and resources ('debt', 'payment plan', 'interest'). It distinguishes from siblings by focusing specifically on debt payoff calculations rather than general interest calculations (compound_interest), loan comparisons (loan_comparison), or other financial tools.

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 provides clear context about when to use this tool: for calculating debt payoff timelines and interest costs, comparing base vs. accelerated payment plans. However, it doesn't explicitly state when NOT to use it or mention specific alternatives among the sibling tools (like when to choose loan_comparison instead).

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