accounting.ratios

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

Annotations already mark it read-only, idempotent, and closed-world, so the low bar is met, yet the description adds substantial beyond-schema behavior: 50-digit internal precision, HALF_EVEN rounding to decimals, error on zero denominators, and that results are multiples not percentages. These are genuinely useful invocation-shaping facts.

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?

Front-loaded with the eight ratios then the precision/rounding/error details; every sentence carries real information. It is dense and the error/percentage clauses run together, but nothing is wasted.

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 an output schema exists (return values need not be spelled out) and the tool is read-only, the description covers everything an agent needs: what it computes, precision, rounding, units, and failure conditions.

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 coverage is 0%, so the description must compensate, and it does well: it clarifies decimals (non-negative integer, default 4, out-of-range is an input error), defines amounts as finite Decimal strings, and specifies that four specific denominators erroring is the failure mode. It stops short of documenting each amount parameter's sign/validity individually.

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 action (calculate 8 ratios at once) and explicitly enumerates all eight ratios, plus names the input sources (balance sheet and income statement). An agent immediately knows what this produces and from what inputs.

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 'at once' framing implies this is the batch ratio tool, but there is no explicit guidance on when to prefer it over siblings like dupont_3, dupont_5, or finance.roi, nor any 'when not to use' exclusions. Usage is only implied.

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