payback_period

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

No annotations are provided, so the description carries full burden for behavioral disclosure. It states it 'calculates' but doesn't clarify if this is a read-only computation, whether it modifies data, what permissions might be needed, or what the output looks like. For a calculation tool with zero annotation coverage, this leaves significant behavioral gaps.

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 at four words, with no wasted language. It's front-loaded with the core action and resource. While it may be too brief for completeness, as a standalone statement it's efficient and well-structured.

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 tool has 4 parameters with low schema coverage (25%), no annotations, and no output schema, the description is inadequate. It doesn't explain the calculation method, output format, or error conditions. For a financial calculation tool with multiple inputs, this leaves too much undefined for effective use.

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 description coverage is low at 25%, with only 'discountRate' having a description. The tool description doesn't add any parameter details beyond the name, failing to explain what 'initialInvestment' or 'cashFlows' represent, or the implications of the 'discounted' boolean. It doesn't compensate for the schema's lack of descriptions, so it meets the baseline but doesn't add value.

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 'Calculate payback period for investment' clearly states the verb ('calculate') and resource ('payback period'), but it's somewhat vague about scope and doesn't differentiate from sibling tools like 'analytics_scenario_comparison' or 'property_investment_analysis' that might also involve investment calculations. It's functional but lacks specificity about what makes this tool unique.

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 no guidance on when to use this tool versus alternatives. With many sibling tools for financial analysis (e.g., 'calculate_npv', 'calculate_irr', 'profitability_index'), there's no indication of when payback period is preferred or what context it's suited for. It's a bare statement of function with no usage context.

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