calculate_payout_period

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

With no annotations, the description carries full burden. It explains the algorithm (first month where cumulative cash flow >= 0) but lacks mention of edge cases like never paying back or handling of non-monthly intervals.

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 extremely concise, front-loading the purpose, then algorithm, then parameter explanation. Every sentence earns its place with no redundancy.

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 presence of an output schema (not shown) reduces the need to describe return format. The description covers what the tool does and how it works, though it could mention potential edge cases like non-recovery.

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?

Despite zero schema description coverage, the description fully explains the cash_flows parameter: it specifies monthly periods, dollar currency, and that the first element is typically negative for capex.

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 calculates payout period in months, using a specific verb and resource. It distinguishes itself from sibling tools like calculate_npv and calculate_irr by focusing on payback time.

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 usage for investment recovery analysis but does not explicitly state when to use it over alternatives or when not to use it (e.g., if cash flows are irregular or non-monthly).

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