accounting.dupont_5

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

Annotations already guarantee read-only, idempotent, closed-world behavior, and the description adds genuinely new traits: all amounts must be passed as Decimal strings, five specific inputs must be non-zero, and results are HALF_EVEN-rounded to 6 places by default. It stops short of stating units or an error shape, but that is a minor residual gap.

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?

Three dense sentences: formula first, then validity constraints, then precision rules — front-loaded and free of filler. Nothing is redundant, though the formula is compact enough that it requires careful reading.

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?

For a 7-parameter pure-calculation tool with an output schema already present, the description covers inputs, domain constraints, and rounding, which is essentially everything an agent needs. The only omission is whether ROE is returned as a ratio or a percentage.

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 0%, so the description carries the whole burden, and it does: it maps each argument to its formula role (net_income, pretax_income, ebit, revenue, total_assets, total_equity), declares the string/Decimal format, and documents the decimals default and rounding mode. Only the exact meaning of total_equity in the leverage term is left implicit.

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?

States a specific verb (compute) and a precisely defined resource (5-stage DuPont decomposition of ROE), and spells out the exact factor chain from net income down to financial leverage. That formula alone separates it from accounting.dupont_3 and accounting.ratios without opening any schema.

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 never says when to reach for this instead of dupont_3 or accounting.ratios; the only conditional content is a data-validity constraint (denominators must be non-zero), not a routing rule. An agent must infer the choice from the factor count in the name.

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