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

Annotations already provide readOnlyHint and idempotentHint, covering the safety profile. The description adds that the output is a percentage and specifies the exact formula (net income / total assets), which is useful behavioral context beyond the structured data. It does not mention edge cases like division by zero, but this is acceptable for a simple math tool.

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, efficient sentence that conveys the tool's purpose and formula with no wasted words. It is appropriately sized and front-loaded.

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 simple two-parameter math tool with a documented output schema and safety annotations, the description provides the essential formula and unit. It does not cover edge cases like zero total assets, but the tool's inherent simplicity makes this acceptable.

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?

The schema has 100% coverage for both parameters (net income, total assets). The description clarifies the relationship between them as a ratio and states the result is a percent, adding meaningful context beyond the schema's minimal descriptions.

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 specifies the tool computes Return on Assets as net income divided by total assets, expressed as a percent. This precise formula distinguishes it from sibling tools like roe and roi.

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 the tool is used for calculating Return on Assets, but it does not explicitly state when to prefer it over alternatives such as ROE or ROI. No exclusions or alternative tool references are provided.

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