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

Annotations already mark it readOnly and idempotent. The description adds behavior context: it returns months, total interest, payoff order, and flags insolvent budgets, plus explains the effects of each method ('avalanche minimizes interest, snowball clears accounts soonest'). No contradiction with annotations.

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-loads the core purpose and includes only essential details about methods and output. Every clause adds value; no redundant phrasing.

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 output schema exists and annotations cover safety, the description provides sufficient behavioral details (return values, insolvency flag, method effects). It could mention that insolvency occurs when budget falls below minimum payments, but that's inferable.

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 descriptions cover all 3 parameters (100%). The tool description adds meaning to the 'method' parameter by explaining the strategic trade-off (avalanche vs snowball) and clarifies the role of the fixed monthly budget, going beyond the enum and schema text.

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: creating a multi-debt payoff plan under a fixed monthly budget, with methods and outputs. It distinguishes from siblings like credit-card-payoff by focusing on multi-debt scenarios and named strategies.

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?

Usage is implied by the phrase 'multi-debt payoff plan' – it's for tackling more than one debt. However, it doesn't explicitly note when not to use it or point to alternatives such as credit-card-payoff or loan-payoff for single-debt cases.

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