calculate_debt_payoff

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

Annotations already declare readOnlyHint and idempotentHint, so the description doesn't need to address mutation. It adds value by disclosing the exact return fields (total months, total interest, payoff order, debt-free date) and the strategy choices, going beyond the annotations' safety profile.

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, front-loaded with the verb 'Calculate.' Every sentence adds information: the first defines the calculation and strategies, the second lists outputs and usage. No redundancy or filler.

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?

There is no output schema, so the description's explicit enumeration of return values (total months, total interest, payoff order, debt-free date) is essential and well-provided. The tool's moderate complexity (3 params) is fully covered by the combination of schema and description, making it complete.

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 input schema already provides detailed descriptions for all three parameters (100% coverage), including the snowball/avalanche semantics for strategy. The description only mentions 'snowball or avalanche' without adding new parameter details, so it meets the baseline but doesn't exceed it.

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 begins with 'Calculate the full payoff timeline for a list of debts using either the snowball or avalanche strategy,' which specifies both the action and the resource. It also lists concrete outputs (total months, total interest, payoff order, debt-free date) and distinguishes itself from sibling tools like compare_snowball_vs_avalanche by focusing on a single comprehensive plan.

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 explicitly states 'Use this when a user wants a concrete payoff plan for their debts,' providing a clear usage context. However, it does not explicitly mention when to prefer sibling tools like compare_snowball_vs_avalanche, so there are no stated exclusions.

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