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

Annotations already disclose read-only and idempotent behavior. The description adds the formula (annual coupon pro-rated by days elapsed over day-count basis), which clarifies the calculation logic. However, it does not disclose edge cases or return format, though the output schema partially covers that. The added value is moderate beyond 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 a single, dense sentence that front-loads the purpose and immediately gives the calculation formula. There is no wasted wording, and it is easily scannable.

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's moderate complexity (4 parameters, output schema, annotations), the description is sufficiently complete. It explains the core calculation and is supported by schema and annotations. Minor gaps like explicit usage guidance are not critical here.

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 100%, so all parameters have descriptions. The description adds the relationship between parameters (days elapsed, day-count basis, coupon rate) but does not provide new parameter-level details. Baseline 3 applies per the rubric.

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: calculating accrued interest since the last coupon. It provides a specific verb (pro-rated) and resource (annual coupon), and explains the calculation methodology. This distinguishes it from sibling tools like bond-price or current-yield by focusing on the accrued interest component.

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 accrued interest calculations but does not explicitly state when to use it over alternatives or provide exclusions. Sibling tools include other bond-related calculators, but no cross-referencing or guidance is offered. Usage is implied rather than explicit.

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